14-3-3η is a novel mediator associated with the pathogenesis of rheumatoid arthritis and joint damage

14-3-3-η interacts with BCL-2 to protect human endothelial progenitor cells from ox-LDL-triggered damage

Oxidized low-density lipoprotein (ox-LDL) causes dysfunction of endothelial progenitor cells (EPCs), and we recently reported that 14-3-3-η can attenuate the damage triggered by ox-LDL in EPCs. However, the molecular mechanisms by which 14-3-3-η protects EPCs from the damage caused by ox-LDL are not fully understood. In this study, we observed that the expression of 14-3-3-η and BCL-2 were downregulated in ox-LDL-treated EPCs. Overexpression of 14-3-3-η in ox-LDL-treated EPC significantly increased BCL-2 level, while knockdown of BCL-2 reduced 14-3-3-η expression and mitigated the protective effect of 14-3-3-η on EPCs. In addition, we discovered that 14-3-3-η colocalizes and interacts with BCL-2 in EPCs. Taken together, these data suggest that 14-3-3-η protects EPCs from ox-LDL-induced damage by its interaction with BCL-2.

Coordinating single-cell and bulk RNA-seq in deciphering the intratumoral immune landscape and prognostic stratification of prostate cancer patients

INTRODUCTION

Prostate cancer is a common cancer among male population. The aberrant expression of histone modifiers has been identified as a potential driving force in numerous cancer types. However, the mechanism of histone modifiers in the development of prostate cancer remains unknown.

METHODS

Expression profiles and clinical data were obtained from GSE70769, GSE46602, and GSE67980. Seruat R package was utilized to calculate the gene set enrichment of the histone modification pathway and obtain the Histone score. Least absolute shrinkage and selection operator (LASSO) and Cox regression analyses were employed to identify marker genes with prognostic value. Kaplan-Meier survival analysis was conducted to assess the efficacy of the prognostic model. In addition, microenvironment cell populations counter (MCPcounter), single-sample gene set enrichment analysis (ssGSEA), and xCell algorithms were employed for immune infiltration analysis. Drug sensitivity prediction was performed using oncoPredict R package.

RESULTS

We screened differentially expressed genes (DEGs) between Histone-high score (Histone-H) and Histone-low score (Histone-L) groups, which were enriched in RNA splicing and DNA-binding transcription factor binding pathways. We retained four prognostic marker genes, including TACC3, YWHAH, TAF1C and TTLL5. The risk model showed significant efficacy in stratification of the prognosis of prostate cancer patients in both internal and external cohorts (p < .0001 and p = .032, respectively). In addition, prognostic gene YWHAH was infiltrated in abundance of fibroblasts and highly correlated with Entinostat_1593 drug sensitivity score and the value of risk score.

CONCLUSION

We innovatively developed a histone modification-related prognostic model with high prognostic potency and identified YWHAH as possible diagnostic and therapeutic biomarkers for prostate cancer. It provides novel insights to address prostate cancer and enhance clinical outcomes, thereby opening up a new avenue for customized treatment alternatives.

Mir-142-3P regulates MAPK protein family by inhibiting 14-3-3η to enhance bone marrow mesenchymal stem cells osteogenesis

Clinical studies have found 14-3-3η to be associated with osteoporosis through undefined mechanisms. We aimed to investigate the role of 14-3-3η in osteoporosis and its potential associations with miRNAs. The Gene Expression Omnibus(GEO) and Human Protein Atlas 1 databases were analyzed to examine both the mRNA and protein expression of 14-3-3η in OP. Gene enrichment analyses were performed to explore the underlying mechanism of 14-3-3η based on DAVID. miRWalk was used to predict the associated miRNAs. The statistics were analysed by R software and SPSS software. 14-3-3η was overexpressed and knock down expressed in BMSCs by lentiviral vector transfecting. And BMSCs were induced by hypoxia. qRT-PCR and Western-Blot verified the expression of mRNA and protein. Scratch assay detected the migration of osteocytes. Co-immunoprecipitation and luciferase assay studied the 14-3-3η targeted protein and miRNA. overexpression and knock down of miRNA to verify the relationship of 14-3-3η and target genes. The 14-3-3η mRNA expression level was low in patients with osteoporosis, as corroborated by immunohistochemical staining images. Functional analyses revealed enrichment of the MAPK-associated cascade. 14-3-3η was correlated with MAPK family proteins and five key miRNAs, including mir-142-3p. In addition, 14-3-3η knockdown in BMSCs increased the mRNA and protein expression levels of Hif-α, VEGF, BMP-2, OPN, OST, and Runx2, and enhanced the cells migration ability. Under hypoxic conditions, Hif-α and BMP-2 protein expression levels were upregulated, whereas those of 14-3-3η and MAPK3 were downregulated. Co-immunoprecipitation experiments showed decreased binding of 14-3-3η to MAPK3. 14-3-3η knockdown produced the same results as hypoxia induction. Adding caspase3 inhibitor and knocking down 14-3-3η again prevented MAPK3 cleavage by caspase3 and inhibited BMP-2 expression. Moreover, under hypoxic conditions, miR-142-3P expression was upregulated and luciferase assays revealed 14-3-3η as its target gene. miR-142-3P overexpression decreased mRNA and protein levels of 14-3-3η and MAPK3, while increasing BMP-2 expression. miR-142-3P knockdown reversed these results. BMSC osteogenesis was suppressed by 14-3-3η, whereas miRNA-142-3p promoted it through the inhibition of 14-3-3η.

14-3-3η Proteins as a Diagnostic Marker, Disease Activation Indicator, and Lymphoma Predictor in Patients with Primary Sjögren Syndrome

BACKGROUND

Primary Sjögren syndrome (PSS) is a chronic, autoimmune, and lymphoproliferative disease of the connective tissue. In patients with PSS, the risk of developing B-cell non-Hodgkin lymphoma (NHL) increases dramatically, with a prevalence of approximately 5%. The 14-3-3 protein isoforms are phospho-serin/phospho-threonine binding proteins associated with many malignant diseases. This study aimed to evaluate the relationship between disease activity parameters and markers predicting lymphoma development in patients with PSS and 14-3-3η proteins.

METHODS

This study was designed as an analytical case-control study. A total of 57 PSS patients and 54 healthy volunteers were included in the study. The European League Against Rheumatism (EULAR) Sjögren syndrome disease activity index (ESSDAI) was used to assess systemic disease activity in PSS. Receiver operating characteristic (ROC) analysis was used to test the diagnostic accuracy measures of the analytical results. Multivariable linear regression analysis was used to evaluate the effects of independent variables on the 14-3-3η protein.

RESULTS

The 14-3-3η protein serum levels were found to be significantly higher in PSS (2.72 [2.04-4.07]) than healthy controls (1.73 [1.41-2.43]) (P<0.0001). A significant relationship was found between 14-3-3η protein levels and ESSDAI group (β=0.385, 95%CI=0.318-1.651, P=0.005), hypocomplementemia (C3 or C4) (β=0.223, 95% CI=0.09-1.983, P=0.048) and purpura (β=0.252, 95% CI=0.335-4.903, P=0.022), which are accepted as lymphoma predictors. A significant correlation was found between PSS disease activity score ESSDAI and 14-33η protein (β=0.496, 95% CI=0.079-0.244, P=0.0002).

CONCLUSION

14-3-3η proteins are potential candidates for diagnostic marker, marker of disease activity, and predictor of lymphoma in PSS patients.

Circ_0000144 acts as a miR-1178-3p decoy to promote cell malignancy and angiogenesis by increasing YWHAH expression in papillary thyroid cancer

Papillary thyroid cancer (PTC) is the most common subtype of thyroid cancer. Circular RNA hsa_circ_0000144 (circ_0000144) is related to the progression of thyroid cancer. However, the mechanism by which circ_0000144 accelerates PTC progression is still unclear. Circ_0000144 and YWHAH were upregulated in PTC tissues and cells, while miR-1178-3p had an opposite result. Circ_0000144 silencing constrained PTC cell growth in vitro and in vivo and induced apoptosis and repressed migration, invasion, and angiogenesis of PTC cells in vitro. Circ_0000144 acted as a molecular sponge for miR-1178-3p, which targeted YWHAH. MiR-1178-3p inhibitor reversed circ_0000144 silencing-mediated influence on PTC cell malignancy and angiogenesis. Furthermore, YWHAH overexpression overturned miR-1178-3p mimic-mediated influence on malignant behaviors and angiogenesis of PTC cells. Notably, circ_0000144 regulated YWHAH expression by adsorbing miR-1178-3p. Circ_0000144 promoted cell malignancy and angiogenesis by regulating the miR-1178-3p/YWHAH axis in PTC, offering a novel mechanism for the malignancy and angiogenesis of PTC cells.

Inhibition of circ_0000144 repressed malignant behaviors and angiogenesis of PTC cells in vitro.

Knockdown of circ_0000144 constrained PTC cell proliferation in vivo.

Circ_0000144 acted as a miR-1178-3p sponge.

YWHAH acted as a downstream target for miR-1178-3p.

Serum 14-3-3η as predictor of clinical remission and progression of structural damage in early rheumatoid arthritis following a treat-to-target strategy in a randomized controlled trial

OBJECTIVE

14-3-3η is a proinflammatory mediator critical to joint destruction in rheumatoid arthritis (RA). We aimed to evaluate serum 14-3-3η for predicting disease activity and radiographic progression in patients with early RA in the double-blinded, randomized OPERA trial.

METHOD

180 patients with early RA were randomized to receive methotrexate (MTX) + adalimumab or MTX + placebo in combination with glucocorticoid injections into swollen joints. Disease activity was measured using the 28-joint Disease Activity Score-C-reactive protein (DAS28-CRP). Clinical remission was defined as DAS28-CRP < 2.6. X-rays of hands and feet were evaluated by the Total Sharp van der Heijde score (TSS). Radiographic progression was defined as exceeding the smallest detectable change (1.8 TSS-units). Serum 14-3-3η was determined by enzyme-linked immunosorbent assay. Multivariate logistic regression models were used to identify predictors of DAS28-CRP remission at 6 months and radiographic progression at 12 months.

RESULTS

Baseline 14-3-3η was a borderline significant independent predictor of radiographic progression at 12 months (odds radio = 1.02, 95% confidence interval 1.00-1.03, p = 0.05). In anti-cyclic citrullinated peptide antibody (ACPA)-negative patients, a moderate/high baseline 14-3-3η concentration increased the risk of radiographic progression at 12 months [4/51 (8%) vs 3/9 (33%), χ2 = 4.823, p = 0.028]. No value of 14-3-3η for predicting achievement of clinical remission was found.

CONCLUSION

Serum 14-3-3η was a borderline significant predictor of radiographic progression, particularly in ACPA-negative patients, but not of predicting achievement of clinical remission. Optimal cut-off levels of 14-3-3η for predicting radiographic progression in RA need further clarification.

Circulating microRNAs differentiate fast-progressing from slow-progressing and non-progressing knee osteoarthritis in the Osteoarthritis Initiative cohort

Introduction:

The objective of this study is to identify circulating microRNAs that distinguish fast-progressing radiographic knee osteoarthritis (OA) in the Osteoarthritis Initiative cohort by applying microRNA-sequencing.

Methods:

Participants with Kellgren–Lawrence (KL) grade 0/1 at baseline were included (N = 106). Fast-progressors were defined by an increase to KL 3/4 by 4-year follow-up (N = 20), whereas slow-progressors showed an increase to KL 2/3/4 only at 8-year follow-up (N = 35). Non-progressors remained at KL 0/1 by 8-year follow-up (N = 51). MicroRNA-sequencing was performed on plasma collected at baseline and 4-year follow-up from the same participants. Negative binomial models were fitted to identify differentially expressed (DE) microRNAs. Penalized logistic regression (PLR) analyses were performed to select combinations of DE microRNAs that distinguished fast-progressors. Area under the receiver operating characteristic curves (AUC) were constructed to evaluate predictive ability.

Results:

DE analyses revealed 48 microRNAs at baseline and 2 microRNAs at 4-year follow-up [false discovery rate (FDR) < 0.05] comparing fast-progressors with both slow-progressors and non-progressors. Among these were hsa-miR-320b, hsa-miR-320c, hsa-miR-320d, and hsa-miR-320e, which were predicted to target gene families, including members of the 14-3-3 gene family, involved in signal transduction. PLR models included miR-320 members as top predictors of fast-progressors and yielded AUC ranging from 82.6 to 91.9, representing good accuracy.

Conclusion:

The miR-320 family is associated with fast-progressing radiographic knee OA and merits further investigation as potential biomarkers and mechanistic drivers of knee OA.

Will 14-3-3η Be a New Diagnostic and Prognostic Biomarker in Rheumatoid Arthritis? A Prospective Study of Its Utility in Early Diagnosis and Response to Treatment

Results

Serum14-3-3η levels were significantly higher in all RA patients than in controls (P < 0.001), its sensitivity was 86.7% and 88.3% in early and established RA patients with a significant difference with RF and ACCP at early disease, and the specificity was 96.7%. There was a significant reduction of 14-3-3η levels 6 months after treatment in the first group (p=0.004), and there was a significant positive correlation between serum 14-3-3η levels and parameters of disease activity and severity.

Conclusion

14-3-3η could be a novel, potent, and efficacious diagnostic, and prognostic marker for RA with high sensitivity, that may become a new therapeutic target for RA.

14-3-3η protein is associated with disease activity and osteoporosis in patients with rheumatoid arthritis

Introduction

This study was designed to explore the potential association of serum 14-3-3η protein level with disease activity and bone mineral density (BMD) in Egyptian patients with rheumatoid arthritis (RA). Patients were recruited from the outpatient clinic at Mansoura University Hospital.

Material and methods

One hundred eighty-eight patients with RA and 192 matched controls were enrolled. The rheumatoid arthritis activity parameters were evaluated in RA patients. Bone mineral density was measured. Serum levels of 14-3-3η protein and IL-6 were estimated for all participants by enzyme-linked immunosorbent assays (ELISA).

Results

Rheumatoid arthritis patients had a significantly higher median serum 14-3-3η protein level compared to matched controls (p ≤ 0.05). Serum level of 14-3-3η protein was significantly correlated with DAS28-ESR (p ≤ 0.05) and serum IL-6 level (p ≤ 0.05). The rheumatoid arthritis-osteoporosis group had significantly higher serum 14-3-3η protein than the RA-osteopenia group and RA-control group. Similarly, the difference of the serum 14-3-3η protein between the RA-osteopenia group and the RA-control group was significant. In the linear regression analysis, the strongest factors that were associated with BMD in RA patients were the serum level of 14-3-3η protein (p ≤ 0.05), IL-6 (p ≤ 0.05) and DAS28-ESR (p ≤ 0.05).

Conclusions

Serum level of 14-3-3η protein was significantly elevated in RA patients compared to controls and is significantly correlated with parameters of activity disease. The RA-osteoporosis group had significantly higher serum 14-3-3η protein than the RA-osteopenia group and RA-control group. Serum 14-3-3η protein can be a promising biomarker to reflect RA activity and predict presence of osteoporosis in RA patients.

14-3-3η Promotes Invadosome Formation via the FOXO3-Snail Axis in Rheumatoid Arthritis Fibroblast-like Synoviocytes

Erosive destruction of joint structures is a critical event in the progression of rheumatoid arthritis (RA), in which fibroblast-like synoviocytes (FLS) are the primary effectors. We previously reported that the ability of RA FLS to degrade extracellular matrix (ECM) components depends on the formation of actin-rich membrane protrusions, called invadosomes, through processes that remain elusive. 14-3-3η belongs to a family of scaffolding proteins involved in a wide range of cellular functions, and its expression is closely related to joint damage and disease activity in RA patients. In this study, we sought to assess the role of 14-3-3η in joint damage by examining its contribution to the invadosome formation phenotype of FLS. Using human primary FLS, we show that 14-3-3η expression is closely associated with their ability to form invadosomes. Furthermore, knockdown of 14-3-3η using shRNAs decreases the level of invadosome formation in RA FLS, whereas addition of the recombinant protein to FLS from healthy individuals promotes their formation. Mechanistic studies suggest that 14-3-3η regulates invadosome formation by increasing Snail expression, a mechanism that involves nuclear exclusion of the transcription repressor FOXO3. Our results implicate the 14-3-3η–FOXO3–Snail axis in promoting the aggressive ECM-degrading phenotype of RA FLS, and suggest a role for this scaffolding protein in cartilage degradation.

Immune regulations by 14-3-3: A misty terrain

The 14-3-3 proteins are known for their functions related to the cell cycle and play a prominent role in cancer-related diseases. Recent studies show that 14-3-3 proteins are also regulators of immune responses and are involved in the pathogenesis of autoimmune and infectious diseases. This focused review highlights the significant and recent studies on how 14-3-3 proteins influence innate and adaptive immune responses; specifically, their roles as immunogens and cytokine signaling regulators are discussed. These revelations have added numerous questions to the pre-existing list of challenges, including understanding the 14-3-3 proteins' mechanism of immunogenicity to dissecting the isoform-specific immune regulations.

The Role of 14-3-3 η as a Biomarker in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic multisystem inflammatory disorder with significant morbidity and mortality. Making an early diagnosis and providing appropriate treatment decisions based on clinical and other parameter results in good disease control. Biomarkers, such as C reactive protein (CRP), anti-cyclic citrullinated peptides (anti-CCP), and erythrocyte sedimentation rate (ESR), have been traditionally used. Recently novel biomarkers are described. This article reviews the evidence behind a novel biomarker 14-3-3 η that has been found to provide additional diagnostic and prognostic information as well as predicting response to treatment. A systematic literature review is presented showing the evidence behind this molecule.

14-3-3η Protein in Rheumatoid Arthritis: Promising Diagnostic Marker and Independent Risk Factor for Osteoporosis

BACKGROUND

Early identification and disease monitoring are challenges facing rheumatologists in the management of rheumatoid arthritis (RA).

METHODS

We utilized enzyme-linked immunosorbent assay (ELISA) to determine 14-3-3η and anticyclic citrullinated peptide antibody (anti-CCP) levels, with rheumatoid factor (RF) level detected by rate nephelometry. The diagnostic value of each index was determined via receiver operating characteristic (ROC) curve, and the association between 14-3-3η and osteoporosis was assessed using multiple logistic regression analysis.

RESULTS

Serum levels of 14-3-3η were 3.26 ng per mL in patients with RA. These levels were helpful in identifying patients with the disease, with the area under the curve (AUC) being 0.879 and 0.853, respectively, from all healthy control individuals and patients with RA. Combining 14-3-3η with RF or anti-CCP increased the diagnostic rate. Logistic regression analysis identified 14-3-3η as an independent risk factor for RA-related osteoporosis (odds ratio [OR], 1.503; 95% confidence interval [CI], 1.116-2.025; P <.01).

CONCLUSIONS

Serum 14-3-3η detection by itself or combined with other serum indices was helpful in differentiating patients with RA. Also, it was a promising biomarker for disease monitoring in RA.

Impending radiographic erosive progression over the following year in a cohort of consecutive patients with inflammatory polyarthritis: prediction by serum biomarkers

BACKGROUND/PURPOSE

To evaluate biomarkers as predictors of impending erosion progression.

METHODS

Variables were measured at baseline and annually up to 5 years in patients with recent-onset polyarthritis treated to zero swollen joints. Erosive status was defined as ≥5 Units in Sharp/van der Heijde Erosion Score; Rapid Erosive Progression (REP) was defined as an increase ≥5 Units in Erosion Scores between consecutive visits. Generalised estimating equations (GEEs) evaluated the effect on REP of positive anticyclic citrullinated peptides (ACPAs) and/or rheumatoid factor (RF), C-reactive protein ˃8.0 mg/L (High-CRP) and 14-3-3η protein ≥0.50 ng/mL (High-14-3-3η), alone and in combinations.

RESULTS

Out of 2155 evaluations in 749 consecutive patients, REP occurred after 186 (8.6%) visits, including 13 (2.2%) in patients recruited since 2010. Only 18/537 (3.4%; 6/411 (1.5%) in non-erosive vs 12/126 (9.5%) in patients already erosive) visits without any positive biomarker were followed by REP; at least one biomarker was positive prior to REP in 168/186 (90.3%) visits. Being positive for all four biomarkers conferred a positive predictive value (PPV) of 30.0% (RR 21.8) in patients non-erosive at the visit versus 35.5% (RR 3.07) in those already erosive. High-14-3-3η increased REP only in visits with High-CRP (eg, RR 2.5 to 3.9 when ACPA also positive) and in patients with non-erosive status (eg, RR from 4.3 to 9.4 when also High-CRP).

CONCLUSIONS

Adding High-14-3-3η to positive antibodies and CRP improves prediction of impending REP. Although REP is becoming rarer, signatures of biomarkers might help to adapt treatment strategies in at-risk individuals, even those already erosive.

Prevalence and significance of serum 14-3-3η in juvenile idiopathic arthritis

BACKGROUND

Prompt diagnosis of juvenile idiopathic arthritis (JIA) is important to avoid long term complications. Elevated serum 14-3-3η levels improve the diagnostic sensitivity of rheumatoid factor (RF) and cyclic citrullinated peptide (CCP) antibody in adult rheumatoid arthritis (RA), and have been associated with more severe phenotype. We investigated the prevalence and clinical significance of serum 14-3-3η in different types of JIA.

METHODS

JIA patients (n = 151) followed by the Pediatric Rheumatology Core at Children's Hospital of Los Angeles were categorized into 5 groups: polyarticular JIA RF+ (PJIA RF+; n = 39), PJIA RF- (n = 39), psoriatic arthritis (PsA; n = 19), enthesitis-related arthritis (ERA; n = 18), and oligoarticular JIA (OJIA [control group]; n = 36). RF, CCP antibody, and 14-3-3η were measured for all patients. 14-3-3η serum levels > 0.2 ng/mL were considered positive. Disease activity was assessed by the Juvenile Arthritis Disease Activity Score-71 (JADAS-71).

RESULTS

Elevated 14-3-3η levels were detected in 34/151 (23%) patients, and across all groups tested. Most patients with 14-3-3η had titers ≥4 times above the cutoff value. The majority (22, 65%) of 14-3-3η-positive patients were also positive for RF or CCP antibodies, 16 (47%) were positive for all 3, and 12 (35%) were single-positive for 14-3-3η. The highest prevalence of 14-3-3η was in PJIA RF+ patients (49%), followed by OJIA (22%). Positivity for 14-3-3η was not significantly associated with disease activity or age at diagnosis.

CONCLUSION

Serum 14-3-3η can be detected in all forms of JIA tested but appears to be most common in PJIA RF+. 14-3-3η does not appear to correlate with disease activity in JIA.

14-3-3η Protein as a Potential Biomarker in Juvenile Idiopathic Arthritis

The 14-3-3η (eta) protein was evaluated as a biomarker in a cohort of patients with juvenile idiopathic arthritis (JIA), as well as disease- and healthy-controls, to determine its potential clinical utility. In this case-control study, levels of 14-3-3η protein were evaluated in archival specimens from patients with JIA, systemic lupus erythematosus (SLE), and rheumatoid arthritis (RA), as well as healthy pediatric controls. Just over 200 patients were evaluated, using specimens banked between 1990 and 2011. Comparisons were made to complete blood cell count (CBC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP) antibodies, and anti-nuclear antibody (ANA) positivity. 14-3-3η at levels 0.2 ng/mL or higher was considered positive. Fisher's exact tests, odds ratios, 95% confidence intervals, and p-values were reported. 14-3-3η positivity was seen in all included JIA subtypes. The rate of positivity was the highest in RF-positive (pos) polyarticular JIA. In the disease and healthy controls, lower rates of positivity were observed. The frequency of 14-3-3η positivity among RF-positive and RF-negative (neg) polyarticular JIA patients, especially at values ≥0.5 ng/mL (associated with poor outcomes in adults), was also highest. Several JIA patients with 14-3-3η positivity developed RF and anti-CCP positivity later in their disease. Significant levels of 14-3-3η can be found in approximately 30% of RF-pos and RF-neg patients with polyarticular JIA. This protein may represent a new biomarker for polyarticular JIA, particularly RF-neg polyarticular JIA.

MMP activation-associated aminopeptidase N reveals a bivalent 14-3-3 binding motif

Aminopeptidase N (APN, CD13) is a transmembrane ectopeptidase involved in many crucial cellular functions. Besides its role as a peptidase, APN also mediates signal transduction and is involved in the activation of matrix metalloproteinases (MMPs). MMPs function in tissue remodeling within the extracellular space and are therefore involved in many human diseases, such as fibrosis, rheumatoid arthritis, tumor angiogenesis, and metastasis, as well as viral infections. However, the exact mechanism that leads to APN-driven MMP activation is unclear. It was previously shown that extracellular 14-3-3 adapter proteins bind to APN and thereby induce the transcription of MMPs. As a first step, we sought to identify potential 14-3-3-binding sites in the APN sequence. We constructed a set of phosphorylated peptides derived from APN to probe for interactions. We identified and characterized a canonical 14-3-3-binding site (site 1) within the flexible, structurally unresolved N-terminal APN region using direct binding fluorescence polarization assays and thermodynamic analysis. In addition, we identified a secondary, noncanonical binding site (site 2), which enhances the binding affinity in combination with site 1 by many orders of magnitude. Finally, we solved crystal structures of 14-3-3σ bound to mono- and bis-phosphorylated APN-derived peptides, which revealed atomic details of the binding mode of mono- and bivalent 14-3-3 interactions. Therefore, our findings shed some light on the first steps of APN-mediated MMP activation and open the field for further investigation of this important signaling pathway.

Evaluation of serum14-3-3η protein and Sema3A levels in rheumatoid arthritis: diagnostic and prognostic value

Background

Serum14-3-3η protein plays an important role in the pathogenesis of rheumatoid arthritis (RA) as it is a joint-derived proinflammatory mediator. Semaphorin3A (Sema3A) plays an immune regulatory and bone remodeling role in many autoimmune diseases. Their role in rheumatoid arthritis needs to be evaluated for diagnostic and prognostic prospective values.

Results

The serum level of protein 14-3-3n was significantly higher in patients with RA than those in healthy controls. Serum 14-3-3η has a significant positive correlation with RF and ACPA, but not with either DAS28, ESR, or CRP. Serum 14-3-3η levels were significantly correlated with radiographically assessed joint damage. Serum Sema3A levels were decreased in rheumatoid arthritis patients compared to controls. There were also negative correlations with disease duration and activity score (DAS28), ESR, CRP, and RF.

Conclusion

The discriminative ability of 14-3-3η was comparable to RF and ACPA enhancing its diagnostic capacity. Sema 3A might serve as a predictive marker for radiographic severity and could have a potential therapeutic role in RA.

Serum 14-3-3η is a Marker that Complements Current Biomarkers for the Diagnosis of RA: Evidence from a Meta-analysis

OBJECTIVE

To systematically evaluate the diagnostic value of 14-3-3η protein for rheumatoid arthritis (RA).

METHOD

Searched PubMed, Web of Science, Embase and China Biology Medicine (CBM) databases comprehensively from inception to May 2020. The evaluation index were the pooled sensitivity, specificity, diagnosis odds ratio (DOR), positive likelihood ratio (PLR), negative likelihood ratio (NLR), as well as the area under the summary receiver operating characteristic (SROC) curves. Meta-Disc 1.4 and RevMan 5.3 were used to analyze all statistics. QUADAS-2 tool was applied to evaluate the quality of eligible studies. Subgroup analysis and meta-regression were used to explore the sources of heterogeneity.

RESULTS

Nine articles containing eleven records were eligible for this meta-analysis. The pooled sensitivity of 14-3-3η was 0.63 (95% CI: 0.60 to 0.66), the pooled specificity was 0.90 (95% CI: 0.88 to 0.91). The pooled PLR and NLR was 6.10 (95% CI: 4.67 to 7.96) and 0.40 (95% CI: 0.33 to 0.48), respectively. The pooled DOR was 15.90 (95% CI: 11.15 to 22.68), and the area under the curve (AUC) was 0.8696. Compared with a single indicator (rheumatoid factor or anti-citrullinated protein antibodies), adding 14-3-3η can bring incremental benefits to the diagnosis of RA. The results of subgroup analysis and meta-regression suggested that the two factors (ethnicity, early vs established RA) we analyzed might not be the source of heterogeneity (P value were 0.0979 and 0.4298, respectively) and there was no publication bias among these articles (P = .42).

CONCLUSION

Serum 14-3-3η protein is a supplementary biomarker in the diagnosis of RA.

Diagnostic accuracy of 14-3-3 η protein in rheumatoid arthritis: A meta-analysis

AIM

To evaluate the overall diagnostic performance of 14-3-3 η protein in patients with rheumatoid arthritis (RA).

METHODS

PubMed, EMBASE, and Web of Science were searched to acquire eligible studies. Articles published in English before 20 February 2020 were included. Quality Assessment of Diagnostic Accuracy Studies 2 was used to evaluate the risk of bias and application concern of the included articles. Pooled analysis of diagnostic indicators of 14-3-3 η protein for RA was conducted by using a random effects model. Subgroup analysis was used to explore the sources of heterogeneity. Deeks' funnel plot asymmetry test was used to evaluate for the presence of publication bias.

RESULTS

A total of 13 studies (1554 positive and 1934 negative participants) were included. The pooled sensitivity and specificity were 0.73 (95% CI 0.71-0.75) and 0.88 (95% CI 0.87-0.90), respectively. The pooled positive/negative likelihood were 5.98 (95% CI 4.39-8.14) and 0.28 (95% CI 0.21-0.37), respectively. In addition, the pooled diagnostic odds ratio was 23.48 (95% CI 13.76-40.08) and the area under curve was 0.9245. The results of subgroup analysis indicated that ethnicity and control group might be the source of heterogeneity. The results of sensitivity analysis were stable. No significant publication bias was found.

CONCLUSIONS

The current evidence indicated that 14-3-3 η protein has moderate accuracy for the diagnosis of RA.

Value of serum collagen triple helix repeat containing-1(CTHRC1) and 14-3-3η protein compared to anti-CCP antibodies and anti-MCV antibodies in the diagnosis of rheumatoid arthritis

INTRODUCTION

Serological markers are important in the diagnosis of rheumatoid arthritis (RA) and other connective tissues diseases This study explored the clinical value of collagen triple helix repeat containing-1 (CTHRC1) and 14-3-3η protein, compared to routine markers, in the diagnosis of RA.

METHODS

We recruited 103 RA patients, 105 non-RA patients (osteoarthritis, ankylosing spondylitis, systemic lupus erythematosus) and 59 healthy controls. CTHRC1, 14-3-3η, anti-cyclic citrullinated peptide antibody (anti-CCP), anti-mutated citrullinated vimentin antibody (anti-MCV), rheumatoid factor and erythrocyte sedimentation rate (ESR) levels were measured, and their diagnostic value for RA evaluated and compared.

RESULTS

All laboratory indices were elevated in RA (P < 0.05). Of these, anti-MCV had the highest sensitivity (86.4%) and anti-CCP the highest specificity (94.5%). The areas under the curve (AUC) of CTHRC1, 14-3-3η, anti-CCP, anti-MCV, rheumatoid factor and ESR were 0.84, 0.81, 0.89, 0.91, 0.85 and 0.77 respectively (all P < 0.01). Anti-CCP and anti-MCV were the most valuable in the diagnosis of RA. The combination of anti-CCP and anti-MCV had the maximum Youden index, followed by the combination of anti-CCP and 14-3-3η. Binary logistic regression analysis showed that 14-3-3η had the largest odds ratio value (95% CI) at 5.1 (2.1-12.5) for RA.

CONCLUSION

CTHRC1 and 14-3-3η are promising serological indicators of RA, and when combined with anti-CCP, anti-MCV and ESR, can improve the diagnosis of this disease.

Serum levels of 14-3-3η are associated with increased disease risk, activity and duration of rheumatoid arthritis in Chinese patients

The aim of the present study was to determine the association between serum 14-3-3η expression levels and disease risk, inflammation level and disease duration in Chinese patients with rheumatoid arthritis (RA). A total of 45 Chinese patients with RA, 45 patients with osteoarthritis (OA) and 44 age- and sex-matched (with the RA group) healthy control (HC) subjects were consecutively recruited for the present case-controlled study. In addition, the demographic and clinicopathological characteristics of the patients with RA were collected. Serum samples were obtained from patients with RA, patients with OA and the HCs, and the serum levels of 14-3-3η were determined by ELISA. Compared with that in the OA patients (P=0.006) and HCs (P<0.001), 14-3-3η expression was significantly increased in RA patients, and receiver operating characteristics (ROC) analysis indicated that it served as a potential predictive marker for the risk of RA. In patients with RA, serum levels of 14-3-3η were positively correlated with disease duration (P=0.003), erythrocyte sedimentation rate (P=0.006) and disease activity score in 28 joints (P=0.025). The proportion of rheumatoid factor (RF)-positive patients (P=0.023) and anti-citrullinated protein antibody (ACPA)-positive patients (P=0.002) with RA was increased (when 14-3-3η expression was increased) compared with RF-negative patients or ACPA-negative patients, respectively. Of note, 14-3-3η serum levels were able to distinguish patients with established RA (disease duration, >2 years) from patients with early RA (disease duration, ≤2 years) with an AUC of 0.759 (95% CI, 0.612-0.905), and the sensitivity and the specificity at the best cut-off point (14-3-3η=0.613 ng/ml) were 79.3 and 75.0%, respectively. Furthermore, 14-3-3η was able to differentiate between RF-positive RA patients and RF-negative patients or HCs. In conclusion, circulating 14-3-3η expression may serve as a novel biomarker for disease risk and activity of RA in Chinese patients.

The association among 14-3-3η protein, inflammation, bone remodeling and osteoporosis in patients with rheumatoid arthritis

Objective:

To evaluate the correlation among 14-3-3η protein, inflammation, bone remodeling and osteoporosis in patients with rheumatoid arthritis.

Methods:

In this cross-sectional study, the RA patients treated in our hospital were analyzed between January 2015 and November 2019. Bone mineral density was measured using dual energy X-ray absorptiometry, and at the beginning of the study, serum samples were collected and the level of 14-3-3η, TNF-α, and IL-6 was tested using the quantitative enzyme-linked immunosorbent assay, and I-CTX and PINP were measured using automatic electrochemical luminescence immune-analyzer for all the participants.

Results:

In the current study, 285 patients with rheumatoid arthritis were enrolled and assigned into normal, osteopenia, and osteoporotic group respectively. The level of 14-3-3η and IL-6 presented with the highest value in the osteoporosis group, but the lowest value in the normal group, and there were significant differences in the level of 14-3-3η and IL-6 among the groups (p<0.05), and there was positive correlation between 14-3-3η and IL-6 (p<0.05). There were significant differences in PINP and I-CTX among the three groups (p<0.05), and a significantly positive correlation between I-CTX and 14-3-3η (p<0.05) and a significantly negative correlation between PINP and 14-3-3η (p<0.05) were found.

Conclusion:

There was a significant correlation among 14-3-3η protein, inflammation, bone remodeling and osteoporosis in patients with rheumatoid arthritis, the influence of 14-3-3η on osteoporosis may be contributed to its adjusting inflammation and bone remodeling.

Serum 14-3-3η protein is associated with clinical and serologic features of Sjögren's syndrome in patients with systemic lupus erythematosus: a cross-sectional analysis

INTRODUCTION/OBJECTIVES

Systemic lupus erythematosus (SLE) and Sjögren's syndrome (SS) may coexist and carry a higher risk for future comorbidities. Although 14-3-3η protein is recently a known diagnostic marker in rheumatoid arthritis (RA), its role has not been investigated in SLE. The aim of this study was to compare serum 14-3-3η protein level in SLE and RA patients and to examine its association with clinical and laboratory features in SLE patients.

METHODS

Eighty-four SLE patients and 39 RA patients were included. Sociodemographic, SLE disease activity index (SLEDAI), and damage index were assessed for SLE patients. Data about secondary SS were collected. 14-3-3η was measured by ELISA; titres above 0.19 ng/ml were considered positive.

RESULTS

Serum 14-3-3η protein in SLE was significantly lower than in RA (0.37 ± 0.09 vs 1.5 ± 0.51; p < 0.001). 14-3-3η protein level was comparable between SLE patients with and without arthritis (0.29 ± 0.8 vs 0.15 ± 0.08 respectively; p = 0.20). Serum 14-3-3η protein level was higher in SLE with secondary SS features compared to those without (0.22 ± 0.10 IU/ml vs 0.11 ± 0.04 IU/ml; respectively, p < 0.001). There were no differences in 14-3-3η positivity for other lupus criteria or correlation of 14-3-3η titer with SLEDAI. 14-3-3η protein at 1.11 ng/mL yield a secondary SS diagnostic accuracy of 71%.

CONCLUSIONS

Serum 14-3-3η protein level is high in SLE-associated SS. The 14-3-3η protein level was able to distinguish patients with secondary SS among patients with SLE. Studying the role of 14-3-3η protein in Sjögren's syndrome would be considered in further larger scale studies to confirm the impact of any association. Key Points • Serum 14-3-3η protein level is significantly higher in systemic lupus patients with secondary Sjögren's syndrome (SS) in comparison to those without. • Serum 14-3-3η protein can be used as a useful marker to distinguish patients with secondary SS among patients with systemic lupus. • 14-3-3η protein level shows no difference between systemic lupus patients with and without arthritis.

Tumour necrosis factor alpha promotes secretion of 14-3-3η by inducing necroptosis in macrophages

Background

14-3-3η is an intracellular protein also detected in the serum and synovial fluid of patients with rheumatoid arthritis (RA). It is closely related to disease activity and anti-cyclic citrullinated peptide antibody levels. However, the main source of 14-3-3η and the mechanism of its release into the extracellular space remain unclear. Addressing these two points was the main goal of the current study.

Methods

The source of 14-3-3η was investigated by immunostaining RA synovial tissue. Fibroblast-like synoviocytes, CD4⁺ cells, and macrophages were selected as candidates among the various cell types in the synovial tissue. Phosphorylation of mixed-lineage kinase domain-like pseudokinase (MLKL) and cell death of macrophages were studied by phalloidin staining and electron microscopy after stimulation with an oxidative stress inducer (diamide) or tumour necrosis factor (TNF)-α. Extracellular 14-3-3η protein levels were examined by western blotting.

Results

Macrophages from the synovial tissue from RA, but not osteoarthritis, showed dense and widespread cytoplasmic staining for the 14-3-3η protein, co-localized with peptidylarginine deiminase 4. Swelling and membrane rupture of macrophages were induced by treatment with TNF-α, but not interleukin (IL) 6/soluble IL-6 receptor (sIL-6R). Increased MLKL phosphorylation followed by necroptosis was also induced in TNF-α-stimulated macrophages. Necrostatin-1, a necroptosis inhibitor, antagonized MLKL phosphorylation. High levels of 14-3-3η were detected in the culture supernatants of macrophages stimulated with diamide and TNF-α, but not IL-6/sIL-6R.

Conclusions

Macrophages that highly express 14-3-3η undergo TNF-α-induced necroptosis with damage to the cellular structure, resulting in the secretion of 14-3-3η into the extracellular space. The current study provides a novel mechanism for 14-3-3η level increase in the RA synovial fluid.

Importance of 14-3-3eta, anti-CarP, and anti-Sa in the diagnosis of seronegative rheumatoid arthritis

Background/aim

Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovial inflammation. The study aimed to assess serum 14-3-3eta, anti-CarP, and anti-Sa in seronegative RA (SNRA) patients who were treatment-naïve as well as in healthy subjects. This is the first study in the literature to examine these autoantibodies together in SNRA patients.

Materials and methods

Forty-five treatment-naïve SNRA patients and 45 healthy subjects were recruited. Drugs change the levels of autoantibodies; therefore, patients who took any medication had been excluded from our study. Anti-carbamylated protein, anti-Sa, and 14-3-3eta were measured by using three different ELISA kits.

Results

Median serum concentration of healthy controls in 14-3-3eta was 0.02 (0.02–0.27) ng/mL. Median serum concentration of SNRA patients in 14-3-3eta was 1.00 (0.48–1.28) ng/mL. Data were analyzed with Mann–Whitney U tests; the P-value was <0.001 in 14-3-3eta. Receiver operating characteristic (ROC) curve analysis showed that 14-3-3eta in SNR compared to healthy controls had a significant (P < 0.001) area under the curve (AUC) of 0.90 (95% confidence interval, 0.83–0.96). At a cutoff of ≥0.33 ng/mL, the ROC curve yielded a sensitivity of 88.9%, a specificity of 82.2%, a positive predictive value of 83.3%, and a negative predictive value of 88.1%.

Conclusion

We found that 14-3-3eta can be used as a diagnostic marker in SNRA.

How to investigate: Pre-clinical rheumatoid arthritis

Multiple studies have shown that there is a pre-clinical period preceding the development of rheumatoid arthritis (RA). During this period, complex interactions between the environmental and genetic causes occur, and the expression "preclinical RA" has been proposed to define it. Early treatment intervention is associated with less joint damage and has an increased possibility of achieving remission. In this review, we provide an overview of the preclinical phases of RA, new immunological and imaging biomarkers, and the clinical features, and the management of individuals at-risk of developing RA.

Serologic Diagnosis of Rheumatoid Arthritis

Accurate diagnosis of inflammatory arthritides remains a challenge because of substantial clinical overlap. To achieve a granular classification for informing clinical decisions, numerous potential serologic biomarkers have been identified. Rheumatologists have settled on rheumatoid factor and anti-citrullinated protein antibodies for the diagnosis of rheumatoid arthritis (RA) based on specificity and sensitivity and their ability to be integrated into clinical algorithms. These biomarkers should be interpreted in their specific clinical context. This article discusses the serologic basis for the diagnosis of RA, how these biomarkers have framed conceptualization of the pathogenesis of RA, and the inherent limitations in their use.

14-3-3ζ-A Novel Immunogen Promotes Inflammatory Cytokine Production

The presence of autoantibodies against 14-3-3ζ in human autoimmune diseases indicates its antigenic function. However, neither the cause nor the consequence of this newly-identified antigenic function of 14-3-3ζ protein is known. To address this, we investigated the immunological functions of 14-3-3ζ by studying ex vivo effects on human peripheral blood mononuclear cells (PBMC) proliferation, polarization, and cytokine production. Exogenous 14-3-3ζ promoted PBMC proliferation and T cell polarization toward Th1 and Th17 populations. Significant increases in IFN-γ and IL-17 levels were observed in the presence of 14-3-3ζ. A specific increase in Th1 cells and IFN-γ production provided strong evidence for MHC class II presentation of 14-3-3ζ antigen. Particularly HLA-DRB1^*0401 allele strongly promoted 14-3-3ζ-induced IFN-γ producing cells. In contrast, prednisolone treatment suppressed both 14-3-3ζ-induced T cell polarization and cytokine production. Overall, we show that MHC presentation and the adaptor functions of 14-3-3ζ participate in promoting IFN-γ and IL-17 production, two of the cytokines commonly associated with autoimmune diseases. To the best of our knowledge, this is the first report describing the ex vivo antigenic function of 14-3-3ζ with human PBMC, thereby providing the basis of its immunological role in human diseases.

MicroRNA hsa-miR-623 directly suppresses MMP1 and attenuates IL-8-induced metastasis in pancreatic cancer

Matrix metalloproteinase-1 (MMP1) participates in the metastasis of pancreatic cancer, and its expression can be regulated by endogenous microRNAs (miRs/miRNAs) and exogenous inflammatory factors. Whether miRNAs that potentially modulate MMP1 expression can also attenuate the pro-metastatic effects of its inducer on pancreatic cancer is yet to be completely elucidated. In the present study, a systematic analysis including in silico and bioinformatics analyses, a luciferase reporter assay and an RNA electrophoretic mobility shift assay (EMSA), were used to investigate the interaction between miRNAs and MMP1 mRNA. In addition, wound-healing assays, Transwell assays and xenograft nude mouse models were implemented to investigate the antitumor activities exerted by candidate miRNAs. As a result, hsa-miR-623 was screened as a candidate miRNA that interacts with the MMP1 transcript, and an inverse correlation between the expression of hsa-miR-623 and MMP1 was observed in human pancreatic cancer tissue samples. The EMSA confirmed that hsa-miR-623 was able to directly bind to its cognate target within the 3′-untranslated region of the MMP1 transcript. In addition, transfection of hsa-miR-623 mimics into PANC-1 and BXPC-3 cell lines markedly inhibited the expression of MMP1 at the mRNA and protein levels, and attenuated IL-8-induced MMP1 expression. hsa-miR-623 also decreased IL-8-induced epithelial-mesenchymal transition in PANC-1 and BXPC-3 cells via the underlying mechanism of inhibition of ERK phosphorylation. Consequently, hsa-miR-623 inhibited pancreatic cancer cell migration and invasion in vitro and metastasis in vivo. The results of the present study suggest that hsa-miR-623 represents a novel adjuvant therapeutic target to prevent metastasis in pancreatic cancer.

The Number of Regulatory B Cells is Increased in Mice with Collagen-induced Arthritis

The aim of this study is to investigate changes in regulatory B cells (Bregs) and the expression of related cytokines such as interleukin-10 (IL-10) and transforming growth factor (TGF)-β in a mouse model of collagen-induced arthritis (CIA). A total 20 DBA/1 mice (6-8 weeks old) were randomly divided into control and CIA disease groups. For the CIA disease group, animals were injected intradermally with chicken collagen type II and complete Freund's adjuvant. The calculated arthritis index score of the CIA group was significantly higher than that in control group. Hematoxylin and eosin staining showed tumid synovial cells with irregular arrangement and obvious hyperplasia, with a high degree of inflammatory cell infiltration in CIA model group. Cytometric bead array technology and quantitative RT-PCR indicated that the levels of IL-10 and TGF-β in serum, and synovial cells were significantly increased in the CIA group. The proportion of Bregs in the spleen of the CIA group was significantly increased compared to the control group. In conclusion, our findings demonstrate that the number of Bregs and the expression of TGF-β and IL-10 are enhanced in mice with CIA.

Tomato 14-3-3 Proteins Are Required for Xv3 Disease Resistance and Interact with a Subset of Xanthomonas euvesicatoria Effectors

The 14-3-3 phospho-binding proteins with scaffolding activity play central roles in the regulation of enzymes and signaling complexes in eukaryotes. In plants, 14-3-3 isoforms are required for disease resistance and key targets of pathogen effectors. Here, we examined the requirement of the tomato (Solanum lycopersicum) 14-3-3 isoform (TFT) protein family for Xv3 disease resistance in response to the bacterial pathogen Xanthomonas euvesicatoria. In addition, we determined whether TFT proteins interact with the repertoire of X. euvesicatoria type III secretion effector proteins, including AvrXv3, the elicitor of Xv3 resistance. We show that multiple TFT contribute to Xv3 resistance. We also show that one or more TFT proteins physically interact with multiple effectors (AvrXv3, XopE1, XopE2, XopN, XopO, XopQ, and XopAU). Genetic analyses indicate that none of the identified effectors interfere with AvrXv3-elicited resistance into Xv3 tomato leaves; however, XopE1, XopE2, and XopO are required to suppress symptom development in susceptible tomato leaves. Phospho-peptide mapping revealed that XopE2 is phosphorylated at multiple residues in planta and residues T66, T131, and S334 are required for maximal binding to TFT10. Together, our data support the hypothesis that multiple TFT proteins are involved in immune signaling during X. euvesicatoria infection.

14-3-3η protein: a promising biomarker for rheumatoid arthritis

Effective management of rheumatoid arthritis (RA) depends on early identification followed by timely invention and proper monitoring of treatment responses which remain challenges facing rheumatologists for lacking biomarkers of high sensitivity and specificity. 14-3-3η has been reported to be a novel RA-related biomarker inducing the expression of multiple factors mediating the pathogenesis of RA, and increasing the diagnostic capture when combined with rheumatoid factor and anticyclic citrullinated peptide antibody. Besides, elevated serum 14-3-3η was relevant to more serious joint erosion and worse therapy outcomes. Here, we summarized the emerging knowledge regarding the roles 14-3-3η plays in RA and its clinical implications as diagnostic, prognostic and therapeutic response surrogate as well as potential drug target for RA.

Clinical significance of detecting HLA-DR, 14-3-3η protein and d-dimer in the diagnosis of rheumatoid arthritis

AIM

To investigate the clinical significance of detecting several biomarkers collectively in the diagnosis of rheumatoid arthritis (RA).

METHODS

128 RA patients, 174 non-RA patients and 80 healthy controls were enrolled. HLA-DR4 and HLA-DR53 were detected by the PCR-SSP method, 14-3-3η protein, anti-CCP and anti-Sa were detected by ELISA and DD was detected by latex immunoturbidimetric assay.

RESULTS

The positive rates of HLA-DR4, HLA-DR53, 14-3-3η protein, anti-CCP and anti-Sa were obviously higher in the RA group (43.8, 38.3, 51.6, 80 and 40.6%, respectively); anti-CCP was of highest sensitivity (79.68%), highest specificity (97.5%) and Youden index (0.77). The AUC of 14-3-3η protein, DD, anti-CCP, anti-Sa were 0.813, 0.859, 0.930, 0.861, respectively.

CONCLUSION

All biomarkers were strongly correlated risk factors for RA; the combination of multiple biomarkers might be of help for diagnostic and therapeutic strategies in RA of recent onset.

Elevated serum 14-3-3η protein may be helpful for diagnosis of early rheumatoid arthritis associated with secondary osteoporosis in Chinese population

Osteoporosis (OP) is one of the signs of bone damage in rheumatoid arthritis (RA). The 14-3-3η protein is an inflammatory protein, which has been reported to be associated with rheumatoid arthritis (RA). This is to determine the serum levels of 14-3-3η protein, evaluate its diagnostic value in early RA, and clear out its significance in RA with secondary osteoporosis. Two hundred fifty-nine RA patients and 80 age and sex-matched healthy controls were included. Assays of serum 14-3-3η protein were done for all participants by enzyme-linked immunosorbent assay (ELISA). Dual-energy X-ray absorptiometry (DEXA) was used to measure bone mineral density (BMD). Serum 14-3-3η protein level was significantly high in RA (2.49/4.72), compared with controls (P < 0.0001). Positive rate of 14-3-3η protein in RA was 97.3%, which was higher than that in controls (χ ² = 276.641, P < 0.0001). Serum 14-3-3η protein level in early RA was significantly higher than that in established RA (3.91/4.82 vs 2.01/3.29, Z = 2.624, P < 0.05). The positive rate among three groups (normal control, early RA group, established RA group) differed from each other (χ ² = 131.396, P < 0.0001). Results of ROC curve indicated the cutoff point of 14-3-3η protein for diagnosis of early RA was 0.879 ng/ml (P < 0.0001). Linear correlation analysis found that serum 14-3-3η protein positively correlated with VAS and HAQ (P < 0.0001), negatively correlated with BMD at lumbar spine and femur in RA (P < 0.0001). Serum 14-3-3η protein among groups of bone mass normal (2.73/3.79), osteopenia (3.15/4.86), and osteoporosis (6.34/6.42) was different in early RA patients (χ ² = 7.974, P < 0.05). Serum 14-3-3η protein levels increase significantly in patients with RA (especially in early RA). There are close relationships between serum 14-3-3η protein and clinical symptoms and osteoporosis in patients with RA.

DAMPs, MAMPs, and NAMPs in plant innate immunity

BACKGROUND

Multicellular organisms have evolved systems/mechanisms to detect various forms of danger, including attack by microbial pathogens and a variety of pests, as well as tissue and cellular damage. Detection via cell-surface receptors activates an ancient and evolutionarily conserved innate immune system.

RESULT

Potentially harmful microorganisms are recognized by the presence of molecules or parts of molecules that have structures or chemical patterns unique to microbes and thus are perceived as non-self/foreign. They are referred to as Microbe-Associated Molecular Patterns (MAMPs). Recently, a class of small molecules that is made only by nematodes, and that functions as pheromones in these organisms, was shown to be recognized by a wide range of plants. In the presence of these molecules, termed Nematode-Associated Molecular Patterns (NAMPs), plants activate innate immune responses and display enhanced resistance to a broad spectrum of microbial and nematode pathogens. In addition to pathogen attack, the relocation of various endogenous molecules or parts of molecules, generally to the extracellular milieu, as a result of tissue or cellular damage is perceived as a danger signal, and it leads to the induction of innate immune responses. These relocated endogenous inducers are called Damage-Associated Molecular Patterns (DAMPs).

CONCLUSIONS

This mini-review is focused on plant DAMPs, including the recently discovered Arabidopsis HMGB3, which is the counterpart of the prototypic animal DAMP HMGB1. The plant DAMPs will be presented in the context of plant MAMPs and NAMPs, as well as animal DAMPs.

DAMPs, MAMPs, and NAMPs in plant innate immunity

BACKGROUND

Multicellular organisms have evolved systems/mechanisms to detect various forms of danger, including attack by microbial pathogens and a variety of pests, as well as tissue and cellular damage. Detection via cell-surface receptors activates an ancient and evolutionarily conserved innate immune system.

RESULT

Potentially harmful microorganisms are recognized by the presence of molecules or parts of molecules that have structures or chemical patterns unique to microbes and thus are perceived as non-self/foreign. They are referred to as Microbe-Associated Molecular Patterns (MAMPs). Recently, a class of small molecules that is made only by nematodes, and that functions as pheromones in these organisms, was shown to be recognized by a wide range of plants. In the presence of these molecules, termed Nematode-Associated Molecular Patterns (NAMPs), plants activate innate immune responses and display enhanced resistance to a broad spectrum of microbial and nematode pathogens. In addition to pathogen attack, the relocation of various endogenous molecules or parts of molecules, generally to the extracellular milieu, as a result of tissue or cellular damage is perceived as a danger signal, and it leads to the induction of innate immune responses. These relocated endogenous inducers are called Damage-Associated Molecular Patterns (DAMPs).

CONCLUSIONS

This mini-review is focused on plant DAMPs, including the recently discovered Arabidopsis HMGB3, which is the counterpart of the prototypic animal DAMP HMGB1. The plant DAMPs will be presented in the context of plant MAMPs and NAMPs, as well as animal DAMPs.

A prospective cohort study of 14-3-3η in ACPA and/or RF-positive patients with arthralgia

Background

14-3-3η (eta) is a novel serum/plasma protein biomarker involved in the upregulation of inflammatory and joint damage factors. We analysed the association of 14-3-3η with the development of clinically apparent arthritis in a cohort of subjects with arthralgia and positivity for at least one serologic marker: rheumatoid factor (RF) or anti-citrullinated protein antibody (ACPA).

Methods

Measurement of 14-3-3η in plasma collected on entry into the cohort. For this study, 144 subjects with a minimum of 2.5 (median and maximum 5) years of follow-up were available. The relationship between presence and levels of 14-3-3η and development of arthritis was investigated.

Results

Arthritis occurred in 43 (30 %) of the 144 subjects after a median of 15 months. 14-3-3η was detectable up to 5 years before onset of clinical arthritis and was present significantly more often (36 % versus 14 %; relative risk 2.5, 95 % confidence interval 1.2–5.6; p = 0.02) and at significantly higher levels (median 0.95 versus 0.28 ng/ml; p = 0.02) in subjects developing arthritis compared with those who did not. 14-3-3η levels/positivity and ACPA, but not RF, were univariately associated with the development of arthritis while generalized linear model analysis with RF and ACPA as obligatory factors could not return an incremental benefit with 14-3-3η.

Conclusions

14-3-3η was detectable prior to the onset of arthritis and was associated with arthritis development in arthralgia subjects pre-selected for positivity of RF or ACPA. Its power to predict onset of arthritis independent of ACPA and RF requires a new study in which patients are not pre-selected based on ACPA and/or RF seropositivity.

Serum levels of 14-3-3η protein supplement C-reactive protein and rheumatoid arthritis-associated antibodies to predict clinical and radiographic outcomes in a prospective cohort of patients with recent-onset inflammatory polyarthritis

Background

Age, C-Reactive Protein (CRP) and autoantibodies (Abs) are associated with worse prognosis in patients with recent-onset inflammatory polyarthritis (EPA). Serum 14-3-3η protein is a joint-derived biomarker that up-regulates cytokines and enzymes that perpetuate local and systemic inflammation and may contribute to joint damage. Our objective was to evaluate, over a 5-year prospective period of observation, the additional prognostic potential of serum 14-3-3η protein in EPA patients.

Methods

Clinical variables, serum and radiographs (scored according to the Sharp/van der Heijde (SvH) method) were collected serially. Relationships between serum 14-3-3η protein and other biomarkers were computed with Spearman correlations. Outcomes were Simple Disease Activity Index (SDAI) scores and joint damage progression: ΔSvH for SvH score and ΔErosion for its Erosive component. The additional predictive contribution of 14-3-3η was defined using generalized estimating equations (GEE) and generalized linear mixed models (GLMM).

Results

Among 331 patients, baseline 14-3-3η was ≥0.19 and ≥0.50 ng/ml in 153 (46.2 %) and 119 (36.0 %), respectively; CRP was >8.0 mg/L in 207 (62.5 %), and at least one Ab (Rheumatoid Factor, anti-CCP2 or anti-Sa/citrullinated vimentin) was positive in 170 (51.5 %). Elevated 14-3-3η levels moderately correlated with positive Abs, but not with elevated CRP. Baseline 14-3-3η ≥0.19 ng/ml was associated with more radiographic progression over 5 years. The optimal levels of baseline 14-3-3η to predict radiographic progression was defined by ROC curves at 0.50 ng/ml. Levels of 14-3-3η ≥0.50 ng/ml at baseline were associated with lower likelihoods of ever reaching SDAI remission (RR 0.79 (95 % CI 0.64–0.98), p = 0.03) and higher subsequent progression of Total and Erosion SvH scores. Elevated levels of 14-3-3η during follow-up also predicted higher subsequent progression, even in patients in SDAI remission. Decreases of 14-3-3η levels by at least 0.76 ng/ml and reversion to negative during follow-up associated with less subsequent radiographic progression. In multivariate models, elevated 14-3-3η interacted with positive Abs, elevated CRP and older age to predict subsequent radiographic progression.

Conclusions

Levels of 14-3-3η protein ≥0.50 ng/ml predict poorer clinical and radiographic outcomes in EPA, both at baseline and after initiation of treatment, even in SDAI remitters. 14-3-3η, CRP, age and Abs represent independent predictors of subsequent joint damage.

Trial registration

ClinicalTrials.gov ID: NCT00512239. Registered August 6, 2007.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-016-0935-z) contains supplementary material, which is available to authorized users.

Serum 14-3-3η level is associated with severity and clinical outcomes of rheumatoid arthritis, and its pretreatment level is predictive of DAS28 remission with tocilizumab

INTRODUCTION

Treat-to-target strategies to achieve low disease activity or clinical remission are key in the treatment of rheumatoid arthritis (RA). 14-3-3η is a joint-derived biomarker that is expressed at significantly higher levels in patients with RA than in healthy subjects, other autoimmune diseases, or viral and bacterial arthritides. In this study, we sought to investigate the utility of pretreatment levels of 14-3-3η and serial measurement of 14-3-3η to inform therapeutic outcomes.

METHODS

Serum 14-3-3η levels were measured in 149 Japanese patients with RA before the initiation of therapy and at 1-year follow-up. Patients were treated with either methotrexate (MTX), adalimumab (ADA), tocilizumab (TCZ), or tofacitinib (TOF). 14-3-3η positivity was defined as ≥0.19 ng/ml and at two times and four times this cutoff. In contingency analysis, we determined the association of 14-3-3η with disease severity. Wilcoxon matched-pairs test was used to evaluate the significance of pre- to post-treatment changes. Mann-Whitney U test was performed for differences between treatment response groups. Fisher's exact test was used to assess associations of 14-3-3η with a good response defined by European League Against Rheumatism criteria as well as remission defined by the Disease activity Score in 28 joints with erythrocyte sedimentation rate (DAS28-ESR) and the Clinical Disease Activity Index score.

RESULTS

14-3-3η-positive patients had more severe disease before the initiation of treatment. When combined with C-reactive protein (CRP), 14-3-3η positivity added significantly and incrementally to the identification of patients with high disease activity. 14-3-3η levels were significantly decreased at 1 year and were modifiable across all classes of therapeutics. Patients who reverted to negative 14-3-3η levels had better clinical response than patients who remained positive at 1 year or became positive. Pretreatment 14-3-3η levels informed 1-year DAS28-ESR remission in the TCZ-treated group, in contrast to the ADA, MTX, or TOF groups, while no differences in pretreatment 14-3-3η expression based on clinical response.

CONCLUSIONS

14-3-3η is a modifiable marker in identifying patients with RA in a high disease state. Patients who achieve a negative 14-3-3η status following 1-year of treatment do better clinically with pretreatment 14-3-3η informing response to TCZ.

The pro-inflammatory cytokine 14-3-3ε is a ligand of CD13 in cartilage

Osteoarthritis is a whole-joint disease characterized by the progressive destruction of articular cartilage involving abnormal communication between subchondral bone and cartilage. Our team previously identified 14-3-3ε protein as a subchondral bone soluble mediator altering cartilage homeostasis. The aim of this study was to investigate the involvement of CD13 (also known as aminopeptidase N, APN) in the chondrocyte response to 14-3-3ε. After identifying CD13 in chondrocytes, we knocked down CD13 with small interfering RNA (siRNA) and blocking antibodies in articular chondrocytes. 14-3-3ε-induced MMP-3 and MMP-13 was significantly reduced with CD13 knockdown, which suggests that it has a crucial role in 14-3-3ε signal transduction. Aminopeptidase N activity was identified in chondrocytes, but the activity was unchanged after stimulation with 14-3-3ε. Direct interaction between CD13 and 14-3-3ε was then demonstrated by surface plasmon resonance. Using labeled 14-3-3ε, we also found that 14-3-3ε binds to the surface of chondrocytes in a manner that is dependent on CD13. Taken together, these results suggest that 14-3-3ε might directly bind to CD13, which transmits its signal in chondrocytes to induce a catabolic phenotype similar to that observed in osteoarthritis. The 14-3-3ε-CD13 interaction could be a new therapeutic target in osteoarthritis.