Endothelial cell protein C receptor regulates neutrophil extracellular trap-mediated rheumatoid arthritis disease progression.

Endothelial cell protein C receptor (EPCR) is a 46 kDa transmembrane protein receptor, expressed in most immune cells (T cells, monocytes, dendritic cells, polymorphonuclear neutrophils [PMN]). EPCR reportedly plays a vital role in rheumatoid arthritis (RA). Our results confirmed that EPCR expression exists in the PMN of RA patients, and animal experiments demonstrated that down-regulation of EPCR expression affects disease progression in collagen-induced arthritis (CIA) mice. PMN is the immune cell type that first enters the site of inflammation in the early stages of inflammation. In the early stage of RA, PMN cells migrate into the joint cavity and function in the process of RA synovial inflammation, aggravating the bone destruction found in RA and mediating the progression of RA disease progression. We verified the differences in EPCR expression in PMN cells between RA and osteoarthritis (OA) patients by Western blot and then confirmed this difference in animals. We found that CIA mice treated with PMN-neutralizing antibody intervention had reduced disease performance. On this basis, EPCR was knocked down at the same time. The therapeutic effect of PMN-neutralizing antibody treatment was subsequently diminished. To explore the relationship between EPCR and PMN in RA, we used immunofluorescence to detect the expression of PMN-neutrophil extracellular traps (NETs) in RA patients and used EPCR neutralizing antibodies as an intervention. The results showed that the formation of PMN-NETs in RA patients increased. Finally, through in vitro intervention experiments involving EPCR and PMN transcriptome analysis of the peripheral blood of RA patients, we concluded that EPCR may regulate the formation of PMN-NETs in RA patients through the activated protein C (APC)-EPCR signaling pathway, thereby affecting the progression of disease in RA patients.

Circular RNA Circ_0006282 Promotes Cell Proliferation and Metastasis in Gastric Cancer by Regulating MicroRNA-144-5p/Tyrosine 3-Monooxygenase/Tryptophan 5-Monooxygenase Activation Protein ß Axis.

BACKGROUND: Circular RNAs (circRNAs) are a class of non-coding RNAs which function as novel regulators in human cancers. In this study, we aimed to investigate the functional roles and related molecular mechanisms of circ_0006282 in gastric cancer (GC) progression. METHODS: Fifty-five GC patients were enrolled in this study. GC cells (AGS and HGC-27) and normal cells (GES-1) were cultured in RPMI1640 added with 10% FBS and 1% penicillin-streptomycin. Quantitative real-time polymerase chain reaction (qRT-PCR) assay was used to determine the expression levels of circ_0006282, transcription elongation factor B subunit 1 (TCEB1) mRNA, miR-144-5p and tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein ß (YWHAB; also known as 14-3-3ß). RNase R assay was used to determine the characteristic of circ_0006282. Cell Counting Kit-8 (CCK-8) assay and colony formation assay were employed for cell proliferation. Transwell assay was conducted for cell migration and invasion. Western blot assay was carried out to measure the protein levels of Cyclin D1, matrix metalloprotein 9 (MMP9) and YWHAB. Dual-luciferase reporter assay, RNA pull-down assay and RIP assay were adopted to analyze the interaction between miR-144-5p and circ_0006282 or YWHAB. Murine xenograft model assay was performed to explore the function of circ_0006282 in vivo. RESULTS: Circ_0006282 level was increased in GC tissues and cells compared to normal tissues and cells. Silencing of circ_0006282 restrained GC cell proliferation, migration and invasion. For mechanism analysis, circ_0006282 was identified to function as the sponge for miR-144-5p to positively regulate YWHAB expression in GC cells. Moreover, miR-144-5p inhibition or YWHAB overexpression effectively reversed the impacts of circ_0006282 knockdown on GC cell growth and motility. Additionally, circ_0006282 knockdown blocked tumor growth of GC in vivo. CONCLUSION: Circ_0006282 facilitated the malignant behaviors of GC cells through circ_0006282/miR-144-5p/YWHAB axis.

Elevated levels of soluble Endothelial protein C receptor in rheumatoid arthritis and block the therapeutic effect of protein C in collagen-induced arthritis.

BACKGROUND: Endothelial protein C receptor (EPCR) is a membranous protein that can be combined with a variety of ligands and plays important roles in anticoagulant and anti-inflammation. Recent reports have shown that surface EPCR expression on T cells is negatively associated with Th17 differentiation and is co-expressed with other immunosuppressive molecules, such as The programmed cell death 1 (PD-1) and cytotoxic T lymphocyte-associated antigen-4 (CTLA-4). Hence, we hypothesized that EPCR may play a critical role in rheumatoid arthritis (RA) disease progression that is mediated by Th17 differentiation. In order to explore the role of EPCR on RA disease pathogenesis, we detected membranous EPCR (mEPCR) expression in CD4+ T cells and soluble EPCR (sEPCR) expression in the sera of RA patients. METHODS: The proportion of CD4+/EPCR+ T cells in the peripheral blood of RA patients was detected by flow cytometry, and the expression of sEPCR in the sera of RA patients was detected by enzyme-linked immunosorbent assay (ELISA). For in vitro experiments, protein C (PC) and EPCR recombinant proteins were used to block peripheral blood mononuclear cell (PBMC) activation and to detect Th17 differentiation. For in vivo experiments in DBA/1 mice with collagen-induced arthritis (CIA), we administered PC and EPCR recombinant proteins, monitored disease progression, and evaluated the role of EPCR in disease progression. RESULTS: The proportion of CD4+/EPCR+ T cells in the peripheral blood of RA patients was lower than that of osteoarthritis (OA) patients, while the expression level of sEPCR in the sera of RA patients was concomitantly higher than that in OA patients. Subsequent analysis revealed that sEPCR expression was positively correlated with rheumatoid factors (RF) and other inflammatory indicators in RA patients. Further studies confirmed that sEPCR administration alleviated the progression of collagen-induced arthritis and partially blocked the therapeutic effect of PC in CIA mice. CONCLUSION: Soluble EPCR is associated with RA disease progression and induces disease remission in CIA mice by inhibiting Th17 differentiation.

[Toxicological study of quantum dots].

The excellent optical characteristics of quantum dots make them applied widely in the field of live sciences. Meanwhile, the toxicity of quantum dots have attracted a lot of scientific research staff's attention all around the world. In this paper, the fundamental properties of quantum dots, the progress in quantum dots characteristics, structure, and toxicity were introduced, mainly focusing on the research in cytotoxicity of quantum dots and their influencing factors in recent years.

Macrophage-inducible C-type lectin is associated with anti-cyclic citrullinated peptide antibodies-positive rheumatoid arthritis in men.

BACKGROUND: Macrophage-inducible C-type lectin (MINCLE) is an important member of C-type lectin superfamily, which has been shown evidence for susceptibility to arthritis in animal models. We aimed to investigate the possible association of MINCLE with rheumatoid arthritis (RA) susceptibility in Chinese Han population. METHODS: Haplotypes from HapMap database (Chinese Han Beijing, CHB) were used to select tag-single nucleotide polymorphism (SNP) (r(2) = 0.8) residing in MINCLE gene. A total of 563 patients with RA and 404 healthy controls were TagMan genotyped for SNP rs10841845. Association analyses were performed on the whole data set and on RA subsets based on gender difference and the status of anti-cyclic citrullinated peptide (anti-CCP) antibody in RA patients. Association statistics were calculated by age and sex adjusted logistic regression. RESULTS: Overall, MINCLE SNP rs10841845 was not associated with susceptibility to RA. However, following anti-CCP stratification, rs10841845 GG genotypes conferred a significantly protective effects against anti-CCP-positive RA (OR 0.65, 95%CI 0.430 - 0.995, P = 0.048). Following gender stratification, SNP rs10841845 G allele appeared to insert its RA protective effect only in male patients, both at allele level (G vs. A OR 0.66, 95%CI 0.46 - 0.93, P = 0.018) and at genotype level (GG vs. AA+AG, OR 0.429, 95%CI 0.20 - 0.95, P = 0.036). Notably, the male RA protective effect of rs10841845 G allele was only seen in anti-CCP-positive RA (G vs. A: OR 0.64, 95%CI 0.43 - 0.96, P = 0.029; GG vs. AA+AG: OR 0.375, 95%CI 0.14 - 0.94, P = 0.038). Furthermore, we observed a significant reduction of Disease Activity Score (DAS) 28 score (3.91 ± 0.70 vs. 5.66 ± 0.31, P = 0.022) and serum C-reactive protein levels (31.64 ± 24.13 vs. 91.80 ± 12.02, P = 0.012) in male anti-CCP-positive RA patients carrying rs10841845 GG genotype, compared with patients carrying AA+AG genotypes. CONCLUSIONS: Our study provides the evidence for a gender specific association between MINCLE rs10841845 and RA susceptibility. The SNP rs10841845 G allele appears to have protective effect against anti-CCP-positive RA and confer reduced RA activity in men.

Correction: A Replication Study Confirms the Association of Dendritic Cell Immunoreceptor (DCIR) Polymorphisms with ACPA - Negative RA in a Large Asian Cohort.

[This corrects the article DOI: 10.1371/journal.pone.0041228.].

A replication study confirms the association of dendritic cell immunoreceptor (DCIR) polymorphisms with ACPA - negative RA in a large Asian cohort.

OBJECTIVES: Dendritic cell immunoreceptor (DCIR) has been implicated in development of autoimmune disorders in rodent and DCIR polymorphisms were associated with anti-citrullinated proteins antibodies (ACPA)-negative rheumatoid arthritis (RA) in Swedish Caucasians. This study was undertaken to further investigate whether DCIR polymorphisms are also risk factors for the development of RA in four Asian populations originated from China and Malaysia. METHODS: We genotyped two DCIR SNPs rs2377422 and rs10840759 in Han Chinese population (1,193 cases, 1,278 controls), to assess their association with RA. Subsequently, rs2377422 was further genotyped in three independent cohorts of Malaysian-Chinese subjects (MY_Chinese, 254 cases, 206 controls), Malay subjects (MY_ Malay, 515 cases, 986 controls), and Malaysian-Indian subjects (MY_Indian, 378 cases, 285 controls), to seek confirmation of association in various ethnic groups. Meta-analysis was preformed to evaluate the contribution of rs2377422 polymorphisms to the development of ACPA-negative RA in distinct ethnic groups. Finally, we carried out association analysis of rs2377422 polymorphisms with DCIR mRNA expression levels. RESULTS: DCIR rs2377422 was found to be significantly associated with ACPA -negative RA in Han Chinese (OR 1.92, 95% CI 1.27-2.90, P=0.0020). Meta-analysis confirms DCIR rs2377422 as a risk factor for ACPA-negative RA across distinct ethnic groups (OR(overall) =1.17, 95% CI 1.06-1.30, P=0.003). The SNP rs2377422 polymorphism showed significant association with DCIR mRNA expression level, i.e. RA-risk CC genotype exhibit a significant increase in the expression of DCIR (P=0.0023, Kruskal-Wallis). CONCLUSIONS: Our data provide evidence for association between DCIR rs2377422 and RA in non-Caucasian populations and confirm the influence of DCIR polymorphisms on RA susceptibility, especially on ACPA-negative RA.

Serum IgA against type 3 muscarinic acetylcholine receptor is a novel marker in diagnosis of Sjögren's syndrome.

BACKGROUND: Antibodies against type 3 muscarinic acetylcholine receptor (M3R) are involved in the pathogenesis of Sjögren's syndrome (SS), but the clinical value of them in SS patients has been controversial. The aims of this study were to: (1) establish an improved enzyme-linked immunosorbent assay (ELISA) to detect IgA antibodies against M3R; (2) evaluate the value of IgA antibodies against the second extracellular loop of M3R205-220 (c2M3RP) in diagnosis of SS. METHODS: To increase the ELISA sensitivity, c2M3RP was coupled to bovine serum albumin (BSA) by the glutaraldehyde method and a 96-well microplate was treated by ultraviolet rays before coated. Concentrations of anti-c2M3RP, anti-SSA, and anti-SSB were measured in the sera of 240 individuals: 91 patients with primary SS and 149 controls (16 secondary SS, 27 systemic lupus erythematosus, 40 rheumatoid arthritis and 66 healthy controls). Diagnostic properties of anti-c2M3RP were determined by receiver-operating characteristic curve analysis. RESULTS: The prevalence of serum IgA anti-c2M3RP antibodies in patients with pSS (46%, 42/91) was significantly higher than that in patients with systemic lupus erythematosus (19%, 5/27), in rheumatoid arthritis (15%, 6/40) and in healthy controls (5%, 3/66). However, there was no significant difference between the two SS groups (P = 0.727). The diagnostic performance of IgA anti-M3RP antibodies was similar to anti-SSA assay, but had 22% higher sensitivity than anti-SSB. By analyzing of IgA anti-c2M3RP antibodies, combination of anti-SSA and anti-SSB resulted in increased sensitivity, whereas their specificity was not significantly changed. CONCLUSIONS: The improved anti-c2M3RP ELISA is a novel, sensitive, and specific serological test for the diagnosis of SS. The combined application of anti-c2M3RP, anti-SSA and anti-SSB tests can improve the laboratory diagnosis of SS. The IgA anti-c2M3RP antibodies may serve as a novel diagnostic marker for SS.