Identification and validation of anti-protein arginine methyltransferase 5 (PRMT5) antibody as a novel biomarker for systemic sclerosis (SSc).

OBJECTIVES: In the complex panorama of autoimmune diseases, the characterisation of pivotal contributing autoantibodies that are involved in disease progression remains challenging. This study aimed to employ a global antibody profiling strategy to identify novel antibodies and investigate their association with systemic sclerosis (SSc). METHODS: We implemented this strategy by conducting immunoprecipitation (IP) following on-bead digestion with the sera of patients with SSc or healthy donors, using antigen pools derived from cell lysates. The enriched antigen-antibody complex was proceeded with mass spectrometry (MS)-based quantitative proteomics and over-represented by bioinformatics analysis. The candidate antibodies were then orthogonally validated in two independent groups of patients with SSc. Mice were immunised with the target antigen, which was subsequently evaluated by histological examination and RNA sequencing. RESULTS: The IP-MS analysis, followed by validation in patients with SSc, revealed a significant elevation in anti-PRMT5 antibodies among patients with SSc. These antibodies exhibited robust diagnostic accuracy in distinguishing SSc from healthy controls and other autoimmune conditions, including systemic lupus erythematosus and Sjögren's syndrome, with an area under the curve ranging from 0.900 to 0.988. The elevation of anti-PRMT5 antibodies was verified in a subsequent independent group with SSc using an additional method, microarray. Notably, 31.11% of patients with SSc exhibited seropositivity for anti-PRMT5 antibodies. Furthermore, the titres of anti-PRMT5 antibodies demonstrated a correlation with the progression or regression trajectory in SSc. PRMT5 immunisation displayed significant inflammation and fibrosis in both the skin and lungs of mice. This was concomitant with the upregulation of multiple proinflammatory and profibrotic pathways, thereby underscoring a potentially pivotal role of anti-PRMT5 antibodies in SSc. CONCLUSIONS: This study has identified anti-PRMT5 antibodies as a novel biomarker for SSc.

L-shaped association between serum 25-hydroxyvitamin D and all-cause mortality of individuals with rheumatoid arthritis.

OBJECTIVE: We aimed to examine the relationship between serum 25-hydroxyvitamin D and all-cause, cause-specific mortality of patients with RA. METHODS: This cohort study included 1466 patients with RA from The National Health and Nutrition Examination Survey (NHANES) 2001-14. Mortality status was obtained according to death certificate records from the National Death Index. Cox proportional risk models were used to estimate hazard ratios (HR) and 95% CI for mortality. A generalized additive model, smooth curve fitting and 2-piecewise Cox proportional hazards models were established to address the nonlinearity between serum 25-hydroxyvitamin D and mortality. RESULTS: A total of 1466 patients [mean (s.d.) 59.89 (14.14) years old; 58.94% female] were enrolled. The weighted mean level of 25-hydroxyvitamin D was 59.26 (24.99) nmol/l and 38.95% were found with deficient (or severe deficient) vitamin D (<50.00 nmol/l). During 10453 person-years of follow-up, 268 patients were documented for all-cause death, including 52 cardiovascular disease （CVD）deaths and 48 cancer deaths. Compared with patients with serum 25-hydroxyvitamin D <25.00 nmol/l, patients with higher serum 25-hydroxyvitamin D were more likely to have lower rate of all-cause mortality. Nonlinear and L-shaped association between serum 25-hydroxyvitamin D and all-cause mortality was found, and decreased serum 25-hydroxyvitamin D was significantly associated with increased risk of all-cause mortality in patients with serum 25-hydroxyvitamin D <37.30 nmol/l [HR 0.95 (0.92, 0.98); P < 0.01]. CONCLUSION: An L-shaped association between serum 25-hydroxyvitamin D and all-cause mortality was found among patients with RA, indicating that serum 25-hydroxyvitamin D should be improved to a certain level for the prevention of premature death.

Intestinal uric acid excretion contributes to serum uric acid decrease during acute gout attack.

OBJECTIVE: Spontaneous serum uric acid (SUA) decrease has been found in many patients during acute gout attacks, but its mechanism remains unclear. METHODS: The spontaneous regulation of SUA during a gout attack and its possible causes were evaluated in patients with gout. The mechanism of the spontaneous SUA decrease was further studied in Caco2 cells and a monosodium urate (MSU)-induced gout model of wild-type mice and ABCG2-/- mice. The urate transport function of intestinal epithelial cells was detected by transwell culture of Caco2 cells. Expression of ATP-binding cassette super-family G member 2 (ABCG2), IL-1ß and phosphoinositide 3-kinase (PI3K)/Akt was analysed using real-time PCR, western blotting, or immunofluorescence assays. RESULTS: SUA decreased during acute gout attacks in both the gout patients and MSU-induced gouty mice. Increased serum CRP and IL-1ß levels were correlated with the SUA decrease. Intestinal uric acid excretion and expression of ABCG2 were upregulated in the mice during acute gout attacks. In the ABCG2-/- mice, intestinal uric acid excretion significantly decreased during gout attacks. In an in vitro study of a transwell culture, ABCG2 and its upstream PI3K/Akt pathway were significantly upregulated in intestinal epithelial cells. However, ABCG2 expression and its associated intestinal uric acid transport were inhibited when PI3K/Akt was blocked by a PI3K inhibitor, LY294002. CONCLUSIONS: Increased intestinal urate excretion resulted in spontaneous SUA downregulation during acute gout attacks. Inflammation-induced PI3K/Akt activation and ABCG2 expression in epithelial cells might contribute to the upregulation of intestinal uric acid excretion.

An ankylosing spondylitis risk variant alters osteoclast differentiation.

OBJECTIVE: To explore whether the variants in non MHC proteasome gene are associated with AS and explain the role of the variant in the disease. MATERIAL AND METHODS: Case-control analysis to identify AS predisposition genes; dual-luciferase reporter assay, immunoblot analysis and osteoclastogenesis assays to detect the function of the positive variant. Affected individuals were diagnosed according to the modified New York Criteria by at least two experienced rheumatologists, and rechecked by another rheumatologist. RESULTS: The study included 1037 AS patients and 1014 no rheumatic and arthritis disease controls. The main age of AS onset is between 16 and 35 years old. HLA-B27-positive subjects comprised 90.0% of patients. A nonsynonymous SNP rs12717 in proteasome gene PSMB1 significantly associated with AS. Individuals with CC genotype had a higher onset risk compared with those with GG/GC genotypes (OR = 1.89, P = 0.0047). We also discovered that PSMB1 regulates the receptor activator of nuclear factor-κB (RANK)/RANK ligand (RANKL) signalling pathway and the disease-associated variant PSMB1-Pro11 significantly inhibits RANKL-induced NF-κB pathway in osteoclast differentiation via the degradation of IKK-ß compared with PSMB1-Ala11. RANKL induced osteoclast differentiation was significantly lower in primary monocyte osteoclast precursor from individuals with genotype PSMB131C/31C compared with individuals with genotype PSMB131G/31G. CONCLUSIONS: These results reveal a novel understanding of the bone formation and reabsorbing imbalance in AS. The new bone formation phenotype can be attributed to the inhibition of osteoclast differentiation by a more functional PSMB1 gene.

Blockade of IL-11 Trans-Signaling or JAK2/STAT3 Signaling Ameliorates the Profibrotic Effect of IL-11.

OBJECTIVES: Systemic sclerosis (SSc) is a rare rheumatic disease characterized by vascular damage, dysregulated immune response, and fibrosis. Interleukin-11 (IL-11) is upregulated in SSc. This study aimed to investigate the pathological and therapeutic role of the IL-11 trans-signaling pathway in SSc. METHODS: Plasma IL-11 level was evaluated in 32 patients with SSc and 15 healthy controls, while the expression levels of ADAM10, ADAM17, IL-11, IL-11 Rα, or IL-11 co-stained with CD3 or CD163 in the skin of SSc patients and healthy controls were analyzed. Fibroblasts were treated with IL-11 and ionomycin to evaluate the profibrotic effect of IL-11 trans-signaling pathway. TJ301 (sgp130Fc) and WP1066 (a JAK2/STAT3 inhibitor) intervention groups were set up to investigate the antifibrotic effect of targeting IL-11. RESULTS: Levels of plasma IL-11 were extremely low in most SSc patients and healthy controls. In contrast, levels of IL-11, IL-11 Rα, and ADAM10, but not ADAM17, were significantly elevated in the skin of SSc patients. Moreover, the numbers of IL-11+ CD3+ cells and IL-11+ CD163+ cells were increased in the skin of SSc patients. Besides, IL-11 and ADAM10 were also elevated in the skin and pulmonary of bleomycin-induced SSc mouse. Fibroblasts co-stimulated with IL-11 and ionomycin showed increased expression of COL3 and phosphorylation of STAT3, which could be inhibited by TJ301 or WP1066. TJ301 also ameliorated skin and lung fibrosis in BLM-induced SSc mouse. CONCLUSIONS: IL-11 induces fibrosis in SSc by regulating the trans-signaling pathway. Blockage of sgp130Fc or inhibition of the JAK2/STAT3 pathway could ameliorate the profibrotic effect of IL-11.

Distinct macrophage polarization in acute and chronic gout.

Macrophage polarization mediates the development of inflammatory diseases. However, the polarization status at various stages of gout is not fully understood. Our study aimed to define the evolution of macrophage polarization in acute and chronic gout. Normal human synovium and synovium with tophi were collected for immunofluorescence (IF). Rat gouty joints were collected for joint thickness assessment and pathological evaluation. Tissue mRNA expression of inducible nitric oxide synthase (iNOS) and arginase-1 (Arg-1) were evaluated. Mouse peritoneal macrophages and THP-1 derived macrophages were stimulated by monosodium urate (MSU) crystals and were collected for detection of interleukin (IL) -1ß and IL-37 levels and iNOS/Arg-1 ratio. Arg-1 and IL-37 were highly expressed in normal synovium and synovium with tophi. In rat gouty joints, the inflammatory cell counts and ankle thickness began to increase at 2 h, peaked at 24 h, and was decreased spontaneously. An increase in macrophages preceded the neutrophils infiltration. Infiltration of M1 was positively related with the severity of arthritis. M2 appeared in an early stage (at 2 h) of inflammation. The number of M1 macrophages was comparable to that of M2 from 2 to 12 h and exceeded M2 number at 18 h and 24 h. The ratios of M2/M1 reversed at 48 h and remained reversed until 120 h. In mice gouty joints, iNOS/Arg-1 mRNA ratio was significantly higher than the that in control group at 8 h. The proportion of neutrophils and M1-macrophages reached peak at 4 h in mice model with peritoneal gout. Concentration of IL-1ß and ratio of iNOS/Arg-1 were increased at 6 h, peaked at 48 h, and were then decreased at 72 h in vitro, while the concentration of IL-37 peaked at 2 h and then decreased. In summary, altered macrophage polarization was observed in various stages of gouty inflammation. Macrophages in acute gout were polarized into M1 at early stage and into M2 at later stage while the macrophages in chronic gout mainly were only polarized towards M2. The number of M1 rose with the progression of inflammation. Early increase of M2 was observed, which might be generated directly from M0.

IL-37 blocks gouty inflammation by shaping macrophages into a non-inflammatory phagocytic phenotype.

OBJECTIVE: Interleukin (IL)-37 is a natural suppressor of inflammation. Macrophages play an important role in acute gout flare by dominating the inflammation and spontaneous relief. We have reported that IL-37 could limit runaway inflammation in gout. Here we focus on whether IL-37 inhibits gouty inflammation by altering macrophage functions, and how it does so. METHODS: Macrophage functions were evaluated in terms of phagocytosis, pyroptosis, polarization and metabolism. Phagocytosis and polarization of macrophages were detected by side scattering and double-labelling induced nitrogen monoxide synthase (iNOS)/arginase-1 (Arg-1) using flow cytometry, respectively. Transcription of pyroptosis-related molecules was detected by qPCR. Metabolomics was performed by liquid chromatograph mass spectrometer. Human IL-37 knock-in mice and a model with point mutation (S9A) at mouse Gsk3b locus were created by CRISPR/Cas-mediated genome engineering. MSU was injected into the paws and peritoneal cavity to model acute gout. Vernier calliper was used to measure the thickness of the paws. The mice paws and human synovium tissues or tophi were collected for pathological staining. Peritoneal fluid of mice was used to enrich macrophages to detect polarization. RESULTS: IL-37 promoted non-inflammatory phagocytic activity of macrophages by enhancing phagocytosis of MSU, reducing transcription of pyroptosis-related proteins and release of inflammatory cytokines, protecting mitochondrial function, and mediating metabolic reprogramming in MSU-treated THP-1 cells. These multifaceted roles of IL-37 were partly depended on the mediation of glycogen synthase kinase-3ß (GSK-3ß). CONCLUSIONS: Our study revealed that IL-37 could shape macrophages into a 'silent' non-inflammatory phagocytic fashion. IL-37 may become a potentially valuable treatment option for patients of chronic gout, especially for those with tophi.

Spontaneous tendon rupture in a patient with systemic sclerosis: a case report.

BACKGROUND: Systemic sclerosis (SSc) is an incurable autoimmune disease characterized by progressive skin fibrosis and organ failure. Tenosynovitis is a common musculoskeletal manifestation, but tendon rupture has seldom reported in SSc. CASE PRESENTATION: We present a rare case of a 49-year-old female with SSc who has suffered from bilateral tendon rupture of the fourth and fifth digits with positive antinuclear antibody (ANA) and anti-centromere B antibody, but negative rheumatoid factor in serum. In the extensor tendons of the patient's hands, inflammation, edema, hypertrophy and tendon interruption were detected with ultrasound and magnetic resonance imaging(MRI). Tendon transfer repair surgery was performed and 10 mg/week methotrexate was then used in this patient. Her hand function was improved well with methotrexate and rehabilitation treatment postoperatively. CONCLUSIONS: Early detection of tenosynovitis is necessary to prevent tendon rupture in SSc patients. Ultrasound and Magnetic Resonance Imaging appear to be useful examinations for evaluating tendon pathology for early detection.

Leptin Promotes Monosodium Urate Crystal-Induced Inflammation in Human and Murine Models of Gout.

Gouty arthritis is an inflammatory disease that is triggered by abnormal uric acid metabolism, which is usually attributed to obesity, a risk factor of hyperuricemia and gout attack. A high level of leptin in plasma is a marker of individuals with obesity. Population studies show that leptin promotes obesity-related arthritis, such as osteoarthritis, but it is unknown whether leptin contributes to gouty arthritis, another form of obesity-related arthritis. Our present study showed that the levels of leptin and leptin receptor in patients with active gouty arthritis were elevated. Leptin facilitates the stimulation of human synoviocytes, mouse peritoneal macrophages, and HL-60 cells induced by monosodium urate, leading to higher levels of acute gout-related proinflammatory factors. Leptin obviously exacerbates the inflammation of monosodium urate-induced acute gouty arthritis in wild-type mice, whereas that in leptin-deficient C57BL6/Job/ob mice is markedly alleviated. The proinflammatory effect of leptin in acute gouty arthritis is partly mediated by mTORC1 signaling pathway. Our study reveals that leptin may serve as a novel prevention and treatment target in acute gouty arthritis.

The immune dysregulations in COVID-19: Implications for the management of rheumatic diseases.

The pandemic of COVID-19 has caused global social impact and high health risk. Clinical observations have suggested that elevated levels of inflammatory mediators are associated with disease severities in COVID-19 patients, in which the immunological profiles indicate the hyperactivation of innate immune cells and dysregulated adaptive immune responses. The increasing prevalence and disease progression of COVID-19 has emerged as a pressing challenge for the management of rheumatic patients with immune dysregulations. Here we review the immune dysregulations in COVID-19 and discuss the management of COVID-19 patients with rheumatic diseases.

Epistatic interaction between PKD2 and ABCG2 influences the pathogenesis of hyperuricemia and gout.

BACKGROUND: Genetic background affects serum urate concentration and gout risk, especially regarding these variants in the urate-transporter gene ABCG2. However, the role of epistasis between PKD2 and ABCG2 on the pathogenesis of gout is poorly understood. Here we assess this epistatic interaction in the progression from elevated serum urate to gout. RESULTS: We identified two epistatic interaction pairs (rs2728121: rs1481012 and rs2728121: rs2231137) were associated with urate levels in 4914 Chinese individuals (Pint = 0.018 and 0.004, respectively). Using subgroup analysis for gender and BMI, we found the degree of associations was varied by gender and BMI. The SNP pair rs2728121:rs1481012 influenced urate levels in females and overweight subjects (Pint = 0.006 and 0.022, respectively), but rs2728121:rs2231137 did in males, overweight and normal-weight subjects (Pint = 0.017, 0.047 and 0.013, respectively). Consistent results were also observed in associations between these epistatic interactions with hyperuricemia. Next, the SNP pair rs2728121:rs2231137 was identified to influence the development of gout from both hyperuricemia and healthy (Pint = 0.035 and 0.001, respectively), especially in males (Pint = 0.030 and 0.001, respectively). Furthermore, we demonstrated that interacting regions were enriched by regulatory elements. Finally, we observed a strong gene co-expression pattern between PKD2 and ABCG2 (r = 0.743, P = 5.83E-06). CONCLUSION: Our findings indicate epistasis between PKD2 and ABCG2 influence serum urate concentrations, hyperuricemia and gout risk, thus providing insight into the pathogenesis of gout.

The correlation between interleukin-34 and bone erosion under ultrasound in rheumatoid arthritis.

Background: Rheumatoid arthritis (RA) is a chronic inflammatory arthropathy characterized by excessive synovial hyperplasia and progressive joint destruction. Pro-inflammatory cytokines play major roles in the regulation of synovial inflammation. The contribution of interleukin-34 (IL-34) in RA pathogenesis has been strongly suggested in clinical studies.Aim: To investigate the correlation between plasma IL-34 and disease parameters in RA patients including disease activity score (DAS28), receptor activator of NF-[Formula: see text]B ligand (RANKL) concentration, synovitis and bone erosions under ultrasound.Methods: 60 RA patients and 20 healthy controls were from Huashan Hospital, patient's medical history, physical examination, laboratory examination and ultrasound data were collected and recorded, respectively. Blood samples of all participants were collected and the levels of IL-34 and RANKL were tested. The levels of IL-34 and RANKL in RA patients were compared with those of healthy controls. Furthermore, the correlation between IL-34, RANKL and disease parameters in RA patients was analyzed.Results: Both plasma levels of IL-34 and RANKL in RA patients were significantly higher than the healthy controls (p < .05). IL-34 was significantly related to disease activity scores (r = 0.43, p = .001); RANKL (r = 0.46, p = .0003) and bone erosions by ultrasound (r = 0.38, p = .002).Conclusions: The plasma IL-34 concentration in RA was significantly higher than the healthy controls and was significantly correlated with RANKL, as well as disease activity score and bone erosions by ultrasound. The IL-34 may be a new biological marker for disease activity and predictor for bone erosions in RA. Targeting IL-34 holds promise in the management of RA and, potentially, other osteoclasts driven diseases (erosive osteoarthritis and psoriatic arthritis for example).

IgG Galactosylation status combined with MYOM2-rs2294066 precisely predicts anti-TNF response in ankylosing spondylitis.

BACKGROUND: Tumor necrosis factor (TNF) blockers have a high efficacy in treating Ankylosing Spondylitis (AS), yet up to 40% of AS patients show poor or even no response to this treatment. In this paper, we aim to build an approach to predict the response prior to clinical treatment. METHODS: AS patients during the active progression were included and treated with TNF blocker for 3 months. Patients who do not fulfill ASASAS40 were considered as poor responders. The Immunoglobulin G galactosylation (IgG-Gal) ratio representing the quantity of IgG galactosylation was calculated and candidate single nucleotide polymorphisms (SNPs) in patients treated with etanercept was obtained. Machine-learning models and cross-validation were conducted to predict responsiveness. RESULTS: Both IgG-Gal ratio at each time point and differential IgG-Gal ratios between week 0 and weeks 2, 4, 8, 12 showed significant difference between responders and poor-responders. Area under curve (AUC) of the IgG-Gal ratio prediction model was 0.8 after cross-validation, significantly higher than current clinical indexes (C-reactive protein (CRP) = 0.65, erythrocyte sedimentation rate (ESR) = 0.59). The SNP MYOM2-rs2294066 was found to be significantly associated with responsiveness of etanercept treatment. A three-stage approach consisting of baseline IgG-Gal ratio, differential IgG-Gal ratio in 2 weeks, and rs2294066 genotype demonstrated the ability to precisely predict the response of anti-TNF therapy (100% for poor-responders, 98% for responders). CONCLUSIONS: Combination of different omics can more precisely to predict the response of TNF blocker and it is potential to be applied clinically in the future.

HLA class I and II alleles in susceptibility to ankylosing spondylitis.

OBJECTIVE: To examine associations of HLA class I and class II alleles with ankylosing spondylitis (AS) in three cohorts of patients of European, Asian and African ancestry. METHODS: HLA-A, HLA-B, HLA-C, HLA-DRB1, HLA-DQB1 and HLA-DPB1 alleles were genotyped in 1948 unrelated white and 67 African-American patients with AS from the Prospective Study of Outcomes in Ankylosing Spondylitis cohort, the North American Spondylitis Consortium and Australo-Anglo-American Spondyloarthritis Consortium, 990 white and 245 African-American Controls and HLA-B alleles in 442 Han Chinese patients with AS and 346 controls from Shanghai and Gansu, China. In addition to the case:control analyses, HLA-B*27-negative patients with AS were analysed separately, and logistic regression and 'relative predispositional effects' (RPE) analyses were carried out to control for the major effect of HLA-B*27 on disease susceptibility. RESULTS: Although numerous associations were seen between HLA alleles and AS in whites, among HLA-B*27-negative patients with AS , positive associations were seen with HLA-A*29, B*38, B*49, B*52, DRB1*11 and DPB1*03:01 and negative associations with HLA-B*07, HLA-B*57, HLA-DRB1*15:01, HLA-DQB1*02:01 and HLA-DQB1*06:02. Additional associations with HLA-B*14 and B*40 (B60) were observed via RPE analysis, which excludes the HLA-B*27 alleles. The increased frequency of HLA-B*40:01 and decreased frequency of HLA-B*07 was also seen in Han Chinese and African-Americans with AS. HLA-B*08 was decreased in whites with acute anterior uveitis. CONCLUSIONS: These data, analysing the largest number of patients with AS examined to date in three ethnic groups, confirm that other HLA class I and II alleles other than HLA-B*27 to be operative in AS predisposition.

Sirt1 ameliorates monosodium urate crystal-induced inflammation by altering macrophage polarization via the PI3K/Akt/STAT6 pathway.

OBJECTIVES: Acute gout is an inflammatory response to MSU crystals. In our previous research, Sirt1 was shown to have an effect in preventing acute gouty inflammation. In the current study, we aimed to investigate the underlying mechanism involving Sirt1 in acute gout. METHODS: The cytological changes and Sirt1 expression in the synovium were observed in patients with acute or intermittent gout. The effect of Sirt1 and its mechanism in gout were studied in macrophages, C57BL/6 mice and Sirt1+/- mice. RESULTS: Sirt1 expression was increased in the peripheral blood mononuclear cells (PBMCs) of patients with acute gout but not in the chronic tophus tissue. The arthritis score and numbers of inflammatory cells in injured paw tissue from murine gout models were upregulated in Sirt1+/- mice compared with wild-type mice. A PCR array of the paw tissue from murine gout models indicated that Sirt1 activation might attenuate MSU-induced inflammation by altering the polarization state of macrophages. Furthermore, in patients with acute gout, the phagocytosis of MSU crystals by a macrophage was found in a smear of the joint fluid and large amounts of macrophages were also found in the synovium. The activation of Sirt1 in gouty mice actually decreased the tendency toward M1 polarization. The inhibition of PI3K/Akt partially blocked the anti-inflammatory effect of Sirt1 and the translocation of STAT6, and phosphorylated STAT6 expression was decreased in RAW 264.7 cells treated with MSU crystals. CONCLUSION: Our studies revealed that Sirt1 ameliorates MSU-induced inflammation by altering macrophage polarization via the PI3K/Akt/STAT6 pathway.

Associations of circulating CXCR3-PD-1+CD4+T cells with disease activity of systemic lupus erythematosus.

OBJECTIVES: Which helper CD4+ T cell subset contributes to autoantibodies generation and severity of end-organ involvement in lupus patients remains to be explored. Our research aims to investigate the roles of circulating Tfh (cTfh) cell subsets and corresponding CXCR5- Th cells in lupus patients and their correlation with SLE disease activity index 2000 (SLEDAI). METHODS: Peripheral blood mononuclear cells (PBMCs) were isolated from blood of systemic lupus erythematosus (SLE) patients as well as healthy donors. The proportion of Th cell subsets classified from cell surface markers (CD45RO, CXCR5, CXCR3, CCR6, PD-1, ICOS, and CCR7) is detected by flow cytometry. RESULTS: We found no difference in the frequency of CD45RO+CXCR5+CD4+ T cells between SLE patients and health controls. As previously reported, SLE patients showed an increase in the percentage of CXCR5+PD-1+, CXCR5+ICOS+PD-1+ and CXCR5+CCR7loPD-1hi cTfh subset, however, none of these populations had correlation with SLEDAI. Therefore, we further investigated the CXCR5- subsets, and surprisingly we found that the frequency of CXCR3-PD-1+ subset was correlated with SLEDAI, ds-DNA IgG, anti-nucleosome antibody, C3, and C4 independent of CXCR5. Consistently, CXCR3-PD-1+CD45RO+CD4+T cells expressed factors associated with B-cell-help for the autoantibody production. CONCLUSION: CXCR3-PD-1+CD4+T cells are a sensitive indicator to assess SLE disease activity and might contribute B cell help and the generation of autoantibodies in patients.

Sirtuin1 Protects against Systemic Sclerosis-related Pulmonary Fibrosis by Decreasing Proinflammatory and Profibrotic Processes.

Pulmonary fibrosis is the leading cause of death in systemic sclerosis (SSc). Sirtuin1 (SIRT1) is a deacetylase with known antiinflammatory and antifibrotic activity in the liver, kidney, and skin. The role of SIRT1 in SSc-related pulmonary fibrosis is unknown. In the present work, we determined that the expression of SIRT1 in peripheral blood mononuclear cells of patients with SSc with pulmonary fibrosis is lower than that in patients with SSc without pulmonary fibrosis. In in vivo studies of bleomycin-induced lung fibrosis in mice, SIRT1 activation with resveratrol reduced collagen production when it was administered either prophylactically during the inflammatory stage or after the development of fibrosis. Furthermore, SIRT1 activation or overexpression inhibited tumor necrosis factor-α-induced inflammatory responses in vitro in human fetal lung fibroblasts, depletion of SIRT1 in fibroblasts enhanced inflammation, and these effects were related to changes in the acetylation of NF-κB. In addition, SIRT1 activation or exogenous overexpression inhibited collagen production in vitro, and these manipulations also inhibited fibrosis via inactivation of transforming growth factor-ß/mothers against decapentaplegic homolog and mammalian target of rapamycin signaling. Taken together, our results show that a loss of SIRT1 may participate in the pathogenesis of SSc-related pulmonary fibrosis, and that SIRT1 activation is an effective treatment for both the early (inflammatory) and late (fibrotic) stages of pulmonary fibrosis. Thus, SIRT1 may be a promising therapeutic target in the management of SSc-related pulmonary fibrosis.

Combination of 5-aminolevulinic acid and iron prevents skin fibrosis in murine sclerodermatous graft-versus-host disease.

Scleroderma or systemic sclerosis (SSc) is a clinically heterogeneous rheumatological autoimmune disease affecting the skin, internal organs and blood vessels. There is at present no effective treatment for this condition. Our study investigated the effects of 5-aminolevulinic acid (5-ALA), which is a precursor of haem synthesis, on graft-vs-host disease (GvHD)-induced SSc murine model. Lymphocytes were intravenously injected from donor mice (B10.D2) into recipient BALB/c mice (recombination-activating gene 2 (Rag-2)-null mice) deficient in mature T and B cells to induce sclerodermatous GvHD (scl-GvHD). To investigate the effect of 5-ALA on scl-GvHD, combination of 5-ALA and sodium ferrous citrate (SFC) was orally administered to the recipient mice for 9 weeks. 5-ALA/SFC treatment significantly reduced progressive inflammation and fibrosis in the skin and ears. Furthermore, 5-ALA/SFC suppressed mRNA expression of transforming growth factor-ß, type I collagen and inflammatory cytokines. These results indicate that the 5-ALA/SFC combination treatment has a protective effect against tissue fibrosis and inflammation in a murine scl-GvHD-induced skin and ear inflammation and fibrosis. Furthermore, the efficacy of 5-ALA/SFC suggests important implications of HO-1 protective activity in autoimmune diseases, and therefore, 5-ALA/SFC may have promising clinical applications. These findings suggested that the 5-ALA/SFC treatment may be the potential strategies for SSc.

New Interleukins in Psoriasis and Psoriatic Arthritis Patients: The Possible Roles of Interleukin-33 to Interleukin-38 in Disease Activities and Bone Erosions.

OBJECTIVES: New interleukins (ILs), especially members of IL-1 and IL-12 families, have recently been reported to be involved in the development and regulation of autoimmune and inflammatory diseases. In this study, we aimed to explore the impact of these new ILs in psoriasis (Ps) and psoriatic arthritis (PsA). METHODS: Forty PsA patients, 20 Ps patients, and 20 healthy controls (HCs) were recruited. Blood samples were obtained for detecting the levels of ILs, IL-12/23p40, and tumor necrosis factor α (TNF-α). The severity of skin lesions was assessed by the Psoriasis Area and Severity Index (PASI). Arthritis activities of PsA patients were assessed by the PsA Joint Activity Index. For PsA patients, circulating osteoclastogenesis-related cytokines (osteoprotegerin and receptor activator of nuclear factor-κB ligand) and numbers of osteoclast precursors were evaluated. Radiographic features of affected joints in these patients were scored for erosion, joint-space narrowing, osteolysis, and new bone formation. Correlations among levels of these ILs, Ps, and PsA disease activities and bone erosions were studied. RESULTS: Ps and PsA patients had higher serum levels of TNF-α, IL-12/23p40, and IL-33. Serum levels of IL-34 and IL-35 were higher in PsA patients than in Ps patients and HCs. Patients with pustular Ps had higher serum levels of IL-36α and IL-38 than patients with Ps vulgaris or HCs. Increased serum levels of IL-36α were positively correlated with PASI. CONCLUSION: Certain ILs were elevated in the circulation of patients with Ps and PsA, which might contribute to the pathogenesis of skin lesions and arthritis.

Laboratory Investigation web focus on China.

The vast growth of China's publishing output is a reflection of the increasing strength of Chinese science. The editors of Laboratory Investigation (LI) present a collection of papers that showcases research by authors from institutions across China, highlighting the significant contributions of Chinese scientists to the journal.