cyclin-d1 and Arthritis--Rheumatoid

Circular RNAs (circRNAs) are important regulators on the onset and progression of rheumatoid arthritis (RA). Our purpose is to explore the role and underpin mechanism of circ_0000396 in RA progression.. RA patients (n = 39) and healthy volunteers (n = 33) were recruited from the Affiliated Hospital of Shaanxi University of Chinese Medicine for the present work. Circ_0000396, microRNA-574-5p (miR-574-5p) and R-spondin 1 (RSPO1) RNA levels were analyzed by reverse transcription-quantitative polymerase chain reaction. Cell proliferation was analyzed by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, colony formation assay, and 5-ethynyl-2'-deoxyuridine (EDU) assay. Cell apoptosis was assessed by flow cytometry. Protein expression levels of proliferating cell nuclear antigen (PCNA), Cyclin D1, Cyclin E1, BCL2-associated × protein (Bax), B-cell lymphoma-2 (Bcl2), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and RSPO1 were detected by western blot assay. Enzyme-linked immunosorbent assay (ELISA) was conducted to analyze the secretion of pro-inflammatory cytokines including IL-1β and TNF-α. The interaction between miR-574-5p and circ_0000396 or RSPO1 was confirmed by dual-luciferase reporter assay and RNA-pull down assay.. Circ_0000396 expression was notably down-regulated in RA patients compared with healthy controls. Circ_0000396 overexpression suppressed the proliferation and inflammatory response and triggered the apoptosis of RA synovial fibroblasts (RASFs), accompanied by decreases in PCNA, Cyclin D1, Cyclin E1, Bcl2, IL-1β and TNF-α protein expression and an increase in Bax protein expression. Circ_0000396 acted as a molecular sponge for miR-574-5p, and circ_0000396 overexpression-mediated protective effects on RASFs dysfunction were largely reversed by the introduction of miR-574-5p mimics. miR-574-5p interacted with the 3' untranslated region (3'UTR) of RSPO1, and miR-574-5p negatively regulated RSPO1 expression in RASFs. Circ_0000396 could up-regulate the expression of RSPO1 by sponging miR-574-5p in RASFs. RSPO1 interference largely overturned circ_0000396 overexpression-mediated effects in RASFs.. Circ_0000396 restrained the proliferation and inflammation and induced the apoptosis of RASFs by mediating miR-574-5p/RSPO1 axis, which provided novel potential targets for RA treatment.

Topics: 3' Untranslated Regions; Arthritis, Rheumatoid; Cell Proliferation; Cyclin D1; Humans; Inflammation; MicroRNAs; Proliferating Cell Nuclear Antigen; RNA, Circular; Thrombospondins; Tumor Necrosis Factor-alpha

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease. Several studies reported that fibroblast-like synoviocytes (FLSs) and miRNAs are associated with RA pathogenesis. This study explored the function of miR-653-5p in the regulation of human fibroblast-like synoviocytes-rheumatoid arthritis (HFLS-RA) cells.. The mRNA and protein levels of genes were measured by RT-qPCR and western blot, respectively. MTT, wound healing, and invasion assays were used to evaluate the viability and metastasis of FLSs. Luciferase reporter and RNA pull-down assays were employed to determine the interaction between miR-653-5p and FGF2.. RT-qPCR results demonstrated that miR-653-5p expression was decreased and FGF2 level was increased in synovial tissues and FLSs of RA. Moreover, the viability and metastasis of FLSs were accelerated by miR-653-5p addition, which was restrained by miR-653-5p suppression. Furthermore, we demonstrated that levels of Rac1, Cdc42, and RhoA were decreased after miR-653-5p addition. Besides, luciferase reporter and RNA pull-down assays implied that miR-653-5p targeted the 3'-UTR of FGF2. Functional assays showed that FGF2 overexpression neutralized the suppressive effects of miR-653-5p addition on HFLS-RA cell viability, metastasis, and the levels of Rho family proteins. Meanwhile, the levels of β-catenin, cyclin D1, and c-myc were declined by miR-653-5p supplementation, but enhanced by FGF2 addition.. In sum, we manifested that miR-653-5p restrained HFLS-RA cell viability and metastasis via targeting FGF2 and repressing the Wnt/beta-Catenin pathway.

Topics: Arthritis, Rheumatoid; beta Catenin; Cell Proliferation; Cells, Cultured; Cyclin D1; Fibroblast Growth Factor 2; Fibroblasts; Genes, myc; Humans; MicroRNAs; Real-Time Polymerase Chain Reaction; Synoviocytes

Rheumatoid arthritis (RA) is one of the most critical articular diseases, which is characterized by synovial hyperplasia and impaired quality of life. The clinical features of RA include chronic inflammation of the joints associated with synovial cell overgrowth. However, the mechanism regulating the outgrowth of fibroblast‑like synoviocytes (FLS) is not fully understood. The present study reported that grap2 cyclin D interacting protein (GCIP), an inhibitor of DNA binding/differentiation (ID)‑like helix‑loop‑helix protein, interacted with cAMP‑response element‑binding protein (CREB)‑binding protein (CBP). Furthermore, GCIP repressed CREB‑ and NF‑κB‑dependent gene expression by inhibiting CBP binding to RNA polymerase II complexes. GCIP depletion via small interfering RNA enhanced FLS growth, whereas stable GCIP expression suppressed the growth of 293 cells. In addition, GCIP depletion in FLS induced the expression of cyclin D1, a CREB target gene. The present study identified a novel inhibitory mechanism in which an ID protein may functionally target the transcriptional coactivator CBP. These results suggested that GCIP downregulation may be pivotal in FLS outgrowth.

Topics: Aged; Arthritis, Rheumatoid; Cell Movement; Cell Proliferation; Cells, Cultured; CREB-Binding Protein; Cyclin D1; Down-Regulation; Female; Fibroblasts; Gene Expression Regulation; HEK293 Cells; Humans; Middle Aged; Protein Binding; RNA Interference; Synoviocytes; Transcription Factors

Rheumatoid arthritis, a recurrent incendiary autoimmune joint syndrome, features by prominent synovial hyperplasia. Fibroblast-like synoviocytes are the executive components in the pathogenesis of rheumatoid arthritis. It is generally accepted that excessive proliferation and reduced apoptosis of fibroblast-like synoviocytes lead to synovial hyperplasia. Our previously studies found that sorafenib could inhibit adjuvant arthritis in rats and induced adjuvant arthritis fibroblast-like synoviocytes apoptosis. Presently, we aim to investigate the inhibitory effect with mechanisms of action of sorafenib on adjuvant arthritis fibroblast-like synoviocytes proliferation.. Cell counting kit-8 and flow cytometry detection were conducted to monitor FLSs proliferation and cell cycle. Western blotting and qPCR assays were performed to detect P21, P53, CDK4, CyclinD1 and proliferating cell nuclear antigen content levels.. Sorafenib significantly inhibited adjuvant arthritis fibroblast-like synoviocytes proliferation with an IC50 value of 4 µmol/L by a concentration-dependent pattern, which accompanies by G1 cell cycle arrest. Also, sorafenib significantly decreased the levels of P21, CyclinD1, CDK4 and proliferating cell nuclear antigen, as well as up-regulated P53 expression in adjuvant arthritis fibroblast-like synoviocytes.. Sorafenib could inhibit adjuvant arthritis fibroblast-like synoviocytes proliferation via arresting G1/S cell cycle progression, which was partially through CDK4/CyclinD1-mediated pathway, as well as up-regulating P53 and down-regulating proliferating cell nuclear antigen expressions. These results suggest that sorafenib may provide a new paradigm for rheumatoid arthritis treatment.

Topics: Animals; Antirheumatic Agents; Apoptosis; Arthritis, Experimental; Arthritis, Rheumatoid; Cell Culture Techniques; Cell Cycle; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase 4; Down-Regulation; Fibroblasts; G1 Phase Cell Cycle Checkpoints; Hyperplasia; Mice; Proliferating Cell Nuclear Antigen; Protein Kinase Inhibitors; Rats, Sprague-Dawley; Sorafenib; Synovial Membrane; Synoviocytes

Rheumatoid arthritis (RA) fibroblast-like synoviocytes (RA-FLS) are reportedly involved in RA initiation, progression, and perpetuation. Previously a study showed that retinoid interferon-induced mortality 19 (GRIM19) improved the clinical and histological features of collagen-induced arthritis (CIA),and also inhibited osteoclast formation. However, the role of GRIM19 in RA-FLS remains unclear. In this study, we explored the biological function and underlying mechanism of GRIM19 in cultured RA-FLS. The expression of GRIM19 in synovial tissues and RA-FLS was detected by real-time quantitative RT-PCR(qRT-PCR).The effects of GRIM19 on proliferation, migration, invasion, apoptosis, and inflammatory cytokines levels in RA-FLS were determined using CCK8, wound healing, transwell invasion, and flow cytometry assays, and enzyme-linked immunosorbent assay (ELISA), respectively.GRIM19 and its related protein expression levels were determined by western blot. We found that GRIM19expression was significantly decreased in synovial tissues and FLS from RA patients.GRIM19significantly inhibited proliferation, migration, and invasion; promoted apoptosis; and suppressed inflammatory cytokine secretion by RA-FLS. Moreover, GRIM19 overexpression significantly decreasedthe expression levels of signal transducer and activator of transcription 3(STAT3)and its downstreamproteins,CyclinD1, Bcl-2, and MMP-9. These data indicate that promoting the expression of GRIM19 may yield therapeutic benefits in the treatment of RA.

Topics: Adult; Aged; Apoptosis; Apoptosis Regulatory Proteins; Arthritis, Rheumatoid; Cell Movement; Cell Proliferation; Cyclin D1; Cytokines; Female; Fibroblasts; Humans; Inflammation; Male; Matrix Metalloproteinase 9; Middle Aged; NADH, NADPH Oxidoreductases; Neoplasm Invasiveness; Proto-Oncogene Proteins c-bcl-2; Signal Transduction; STAT3 Transcription Factor; Synovial Membrane; Synoviocytes; Wound Healing

Fibroblast-like synoviocytes (FLS) play an essential role in the pathogenesis of chronic inflammatory diseases, such as rheumatoid arthritis. Paeonol (Pae) is a phenolic compound found in many traditional Chinese medicine remedies. However, the effects of Pae on TNF-α-stimulated FLS and the underlying molecular mechanism are unknown. In this study, we aimed to investigate the anti-proliferative and anti-inflammatory effect of Pae against activated FLS.. Rheumatoid arthritis FLS (RA-FLS) were pre-treated with different doses (25, 50, and 100 µM) of Pae or miR-155 inhibitor for 30 min or transfected with miR-155 mimic, and then treated with 50 ng/mL of tumor necrosis factor alpha (TNF-α) for 1 h. Cells that were untreated served as control. At 24 h after drug pretreatment, the proliferation of FLS was detected using the MTT assay. The concentrations of interleukin IL-6 and IL-1β in cell culture supernatant were examined by enzyme-linked immunosorbent assay (ELISA), and mRNA levels of Foxo3 and miR-155 expression in FLS were quantified by reverse transcription-polymerase chain reaction (RT-PCR). Protein expressions of forkhead box O3 (FOXO3), cyclin D1, and c-Myc were detected by Western Blot.. TNF-α induced the proliferation of FLS, whereas Pae inhibited this proliferation in a dose-dependent manner. Pae attenuated TNF-α-induced production of IL-6 and IL-1β, and inhibited the expression of miR-155 in a dose-dependent manner. In addition, miR-155 inhibitor decreased TNF-α-induced proliferation of FLS, and attenuated TNF-α-induced production of IL-6 and IL-1β. In addition, pretreatment with different doses of Pae or miR-155 inhibitor markedly attenuated TNF-α-induced decrease in protein expression of FOXO3 in FLS. Mechanistic studies revealed FOXO3 as miR-155-5p direct target and inhibition of FOXO3 led to the abolishment of Pae protective effects.. Paeonol protected against TNF-α-induced proliferation and cytokine release of FLS by decreasing the expression of miR-155 and upregulating its target FOXO3.

Topics: Acetophenones; Anti-Inflammatory Agents; Arthritis, Rheumatoid; Cell Proliferation; Cells, Cultured; Cyclin D1; Forkhead Box Protein O3; Humans; Interleukin-1beta; Interleukin-6; MicroRNAs; Proto-Oncogene Proteins c-myc; Synoviocytes; Tumor Necrosis Factor-alpha

Ellipticine (5,11-dimethyl-6H-pyrido[4,3-b]carbazole) is an alkaloid isolated from Apocyanaceae plants. This study was designed to investigate the effects of ellipticine on the proliferation and apoptosis of fibroblast-like synoviocytes (FLSs) from patients with rheumatoid arthritis (RA).. RA-FLSs were exposed to different concentrations of ellipticine (i.e., 0.5, 1, 2, 4 and 8 μM) for 24-72h and measured for viability, proliferation and apoptosis. The involvement of signal transducer and activators of transcription 3 (STAT3) signaling in the action of ellipticine was determined by Western blot analysis, luciferase reporter assay and rescue experiments.. Ellipticine treatment significantly inhibited the viability and proliferation of RA-FLSs in a concentration-dependent manner. In contrast, ellipticine exposure did not alter the viability of normal human FLSs. Moreover, ellipticine triggered significant apoptosis and increased caspase-3 activity in RA-FLSs. Mechanistically, ellipticine reduced the phosphorylation of STAT3 and downregulated the expression of Mcl-1, cyclin D1 and Bcl-2. Luciferase reporter assay demonstrated that ellipticine treatment led to a significant inhibition of STAT3-mediated transcriptional activity in RA-FLSs. Overexpression of constitutively active STAT3 reversed the suppressive effects of ellipticine on RA-FLSs, which was accompanied by restoration of Mcl-1, cyclin D1 and Bcl-2.. Ellipticine shows anti-proliferative and pro-apoptotic effects on RA-FLSs through inhibition of the STAT3 pathway and may have therapeutic potential in RA.

Topics: Apoptosis; Arthritis, Rheumatoid; Caspase 3; Cell Proliferation; Cells, Cultured; Cyclin D1; Down-Regulation; Ellipticines; Fibroblasts; Humans; Myeloid Cell Leukemia Sequence 1 Protein; Proto-Oncogene Proteins c-bcl-2; Signal Transduction; STAT3 Transcription Factor; Synovial Membrane; Synoviocytes; Transcription, Genetic

Rheumatoid arthritis (RA) is an inflammatory disorder of the joints that affects 0.5-1 % of adults. Excessive growth of the fibroblast-like synoviocytes (FLS) promotes hyperplasia of synovial tissues and causes its invasion into the bone and cartilage, which eventually causes deformity and dysfunction of affected joints. Interleukin 35 (IL-35) was shown to suppress the inflammatory responses to collagen-induced arthritis (CIA) via upregulation of T regulatory cells and suppression of T helper type 17 cells in a mouse model. To study the effects of IL-35 on the proliferation and apoptosis frequency of cultured FLS isolated from mice with CIA as well as to examine the effects of IL-35 on CIA in vivo. Thirty DBA/1 J mice, which are used as an animal model for RA, were divided randomly (ten mice per group) to a CIA group (collagen treatment), a CIA + IL-35 group (collagen and IL-35 treatments), and a control group (no treatment). Starting on the 24th day after collagen administration, IL-35 was injected intraperitoneally into mice of the CIA + IL-35 group once per day for 10 days. An arthritis index was calculated, and pathological analysis of synovial tissue was performed. FLS isolated from CIA mice were treated with various concentrations of IL-35 (12.5-100 ng/ml). The MTT assay was used to examine FLS proliferation, and apoptosis frequency of FLS was detected by flow cytometry. On day 24, the CIA mice began to exhibit arthritis symptoms, and the symptoms rapidly progressed with time. Treatment with IL-35 significantly alleviated arthritis symptoms and reduced the synovial tissue inflammation. In addition, IL-35 treatment inhibited proliferation and promoted apoptosis in cultured FLS from CIA mice in a dose-dependent manner. IL-35 could ameliorate the symptoms of arthritis in the CIA mouse model in vivo and inhibited FLS proliferation while promoting FLS apoptosis in vitro, thereby exhibited the potential in inhibiting the progression of RA.

Topics: Animals; Antirheumatic Agents; Apoptosis; Arthritis, Experimental; Arthritis, Rheumatoid; Cell Cycle Checkpoints; Cell Proliferation; Cells, Cultured; Cyclin D1; Down-Regulation; Drug Evaluation, Preclinical; Gene Expression; Interleukins; Male; Mice, Inbred DBA; Synoviocytes

The differences in drug efficacy and adverse reactions may be caused by genetic variations in drug metabolism between individuals.. The aim of the study was to evaluate the effect of gene polymorphisms on the efficacy of therapy and side effects in patients with rheumatoid arthrit s (RA) treated with methotrexate (MTX).. A total of 273 Caucasian patients with RA were treated with MTX for at least 6 months or stopped MTX because of adverse effects. Seven polymorphisms (RFC-1 c.80G>A, GGH c.-401C>T, MTHFR c.1298A>C and c.677C>T, TYMS 2R/3R, TYMS 6-bp deletion, and TCII c.593T>C) were examined for their effects on MTX efficacy and toxicity. Genomic DNA was obtained from peripheral blood leukocytes.. Of all patients, 53% reported some adverse effects during at least 1 visit, which led to MTX withdrawal in 17% of the patients. Adverse effects were more frequent in patients with the MTHFR 677T allele than in those with the 677CC genotype (odds ratio [OR], 1.97; P = 0.01) and in those with the GGH 401CC genotype than in those with the GGH 401CT and TT genotypes (OR, 3.8; P = 0.05). Furthermore, the MTHFR 677T allele was associated with increased activity of aminotransferases (OR, 3.4; P = 0.02). MTX-related hepatotoxicity and alopecia were more common in patients with the RFC-1 80AA genotype (OR, 3.5, P = 0.01; OR, 2.4, P = 0.04; respectively). A more rapid positive response to MTX therapy was demonstrated in MTHFR 677CC homozygotes (OR, 3.4; P = 0.001). There were no other associations between single -nucleotide polymorphisms and the efficacy of MTX treatment.. The MTHFR 677CC and GGH 401TT and CT genotypes were associated with a reduction in the number of MTX-related adverse events. Future allele and genotype analyses may help identify the subsets of RA patients with an increased risk of adverse effects.

Topics: Antirheumatic Agents; Arthritis, Rheumatoid; Cyclin D1; Female; Gene Frequency; Humans; Male; Methotrexate; Methylenetetrahydrofolate Reductase (NADPH2); Polymorphism, Genetic; Polymorphism, Single Nucleotide; Reduced Folate Carrier Protein; Thymidylate Synthase

Rheumatoid arthritis (RA) is a chronic systemic auto- immune disease characterized by joint synovitis. Recent evidence suggests that rheumatoid arthritis synovial fibroblasts (RASFs) promote joint destruction. In this study, we investigated the role of microRNA-26b (miR-26b) in cell proliferation and inflammatory cytokine secretion using patient-derived Rheumatoid arthritis fibroblast-like synoviocyte (RAFLS) to understand pathways influencing rheumatoid arthritis.. RAFLS were cultured in vitro and transfected with miR-26b mimics (experimental group) and negative sequence (control group). The protein levels of Wnt4, Wnt5ɑ, GSK-3β, CyclinD1, Ser9-GSK-3β and β-catenin were detected by western blot analysis. Tumor Necrosis Factor-ɑ (TNF-ɑ), IL- 1β, and IL-6 levels were quantified by Enzyme-linked Immunosorbent Assay (ELISA). RAFLS proliferation and apoptosis were measured by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide (MTT) assay and flow cytometry, respectively.. GSK-3β and CyclinD1 expression levels were lower in miR-26b mimic group compared to Mock group and negative control (NC) group. Conversely, GSK-3β and CyclinD1 expression levels were markedly higher in the miR-26b inhibitor group compared to Mock and NC group (P < 0.05). Transfection of miR-26b mimics significantly increased the, levels of Ser9-GSK-3β and β-catenin in comparison to Mock and NC groups, while transfection of miR-26b inhibitors showed the opposite effect. In miR-26b mimic group, TNF-α, IL- 1β and IL-6 levels were lower than the Mock and NC groups, while in miR-26b inhibitor group, these cytokine levels were higher than the Mock and NC groups (P < 0.05). Transfection of miR-26b mimics significantly reduced the cell proliferation of RAFLS, compared to the Mock and NC groups, and miR-26b inhibitors increased the proliferative capacity of RAFLS compared to Mock and NC groups (P < 0.05). The miR-26b mimic group exhibited higher RAFLS apoptosis rate compared to Mock and NC group and miR-26b inhibitor group showed significantly lower RAFLS apoptosis rate compared to Mock and NC groups (P < 0.05).. MiR-26b regulates β-catenin and CyclinD1 levels by inhibiting GSK-3β expression, which in-turn alters the Wnt/GSK-3β/β-catenin pathway to lower RAFLS proliferation and elevate cell apoptosis and the secretion of TNF-α,IL-1β and IL-6 cytokines. Therefore, our results show that miR-26B plays a central role in inhibiting the inflammation associated with rheumatoid arthritis.. The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9063056861547150.

Topics: Apoptosis; Arthritis, Rheumatoid; beta Catenin; Blotting, Western; Cell Proliferation; Cells, Cultured; Cyclin D1; Cytokines; Enzyme-Linked Immunosorbent Assay; Fibroblasts; Genes, Reporter; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Humans; MicroRNAs; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; Synovial Membrane; Transfection; Wnt Signaling Pathway

Methotrexate (MTX) is the first-line treatment option for newly diagnosed rheumatoid arthritis (RA) patients. However, 50-70% of the patients respond to treatment and 30% suffer toxicity.. To identify pharmacogenetic markers of outcome in RA patients treated with MTX.. We analyzed 27 genetic variants in DHFR, TYMS, MTHFR, ATIC and CCND1 genes.. We included 124 RA patients treated with MTX monotherapy. In multivariate analyses two variants in the MTHFR gene were associated with response, rs17421511 (p = 0.024) and rs1476413 (p = 0.0086), as well as one in the DHFR gene, rs1643650 (p = 0.026). The ATIC rs16853826 variant was associated with toxicity (p = 0.039).. MTHFR, DHFR and ATIC genetic variants can be considered as pharmacogenetic markers of outcome in RA patients under MTX monotherapy.

Topics: Adult; Arthritis, Rheumatoid; Biomarkers, Pharmacological; Cyclin D1; Drug-Related Side Effects and Adverse Reactions; Genetic Association Studies; Humans; Hydroxymethyl and Formyl Transferases; Male; Methotrexate; Methylenetetrahydrofolate Reductase (NADPH2); Middle Aged; Multienzyme Complexes; Nucleotide Deaminases; Polymorphism, Single Nucleotide; Tetrahydrofolate Dehydrogenase; Treatment Outcome

Gamma-glutamyl hydrolase (GGH), cyclin D1 (CCND1) and thymidylate synthase (TS) genes encode enzymes that are involved in methotrexate (MTX) action. In a group of 184 RA patients treated with MTX, we have investigated whether selected polymorphisms in these genes modulate MTX efficacy and/or have impact on adverse drug effects (ADEs).. The efficacy of the MTX therapy has been estimated using the disease activity score in 28 joints (DAS28-ESR) based on EULAR criteria and relative DAS28 values (rDAS28). All adverse drug events were recorded. Patients were genotyped for selected polymorphisms of the GGH (-354 G > T and 452 C > T), CCND1 (870 A > G) and TYMS (variable number of tandem repeats, VNTR, and G to C substitution of triple repeat, 3R allele) gene. Association studies have been performed between obtained genotypes and the efficacy and toxicity of MTX.. According to the EULAR response criteria, 146 RA patients (79.3 %) were classified as responders (good/moderate response) and 38 (20.7 %) as non-responders (poor response). Higher frequency of the TYMS 3 G/3 G genotype has been found among non-responders as compared to individuals with remaining genotypes (p = 0.02). ADEs were recorded in 53 patients. Among those patients eight experienced bone marrow toxicity, all of them carried GGH -354GG genotype (p = 0.003). No other significant association were observed.. The 3 G/3 G genotype of the TYMS gene may indicate predisposition of poor response to MTX and GG genotype of GGH -354 T > G polymorphism may have high predictive value for myelosuppression in RA patients.

Topics: Adult; Aged; Aged, 80 and over; Analysis of Variance; Antirheumatic Agents; Arthritis, Rheumatoid; Bone Marrow; Bone Marrow Diseases; Chi-Square Distribution; Cyclin D1; Female; gamma-Glutamyl Hydrolase; Gene Frequency; Genetic Predisposition to Disease; Humans; Logistic Models; Male; Methotrexate; Middle Aged; Multivariate Analysis; Odds Ratio; Pharmacogenetics; Phenotype; Polymorphism, Genetic; Risk Factors; Severity of Illness Index; Thymidylate Synthase; Young Adult

Rheumatoid arthritis (RA) is an autoimmune disease characterized by the rheumatoid factor and anti-citrullinated peptide antibody (ACPA) against common autoantigens that are widely expressed within and outside the joints. Many factors participate in the pathogenesis of RA, such as cytokine imbalance, Wnt pathway activation, matrix production, and osteoprotegerin on osteoclasts. Fibroblast-like synoviocytes (FLS) activation has an important role in RA pathogenesis. The methyl-CpG-binding protein (MeCP2) which promoted repressed chromatin structure was selectively detected in synovium of diseased articular in rats. Overexpression of this protein results in an up-regulation of global methylation levels and transcriptional suppression of specific genes. There were increased MeCP2 and decreased secreted frizzled-related protein 4 (SFRP4) in synovium as well as the FLS isolated from the synovium of RA rats. Knockdown of MeCP2 using siRNA technique enhanced SFRP4 expression in both mRNA and protein levels in FLS. These results indicated that epigenetic modification was involved in differential expression of SFRP4. To further explore the underlying molecular mechanisms, we hypothesized that the SFRP4 down-regulation in synovium was caused by DNA methylation. Treatment of FLS with DNA methylation inhibitor 5-Aza-2'-deoxycytidine (5-azadC) blocked the cell proliferation and increased the SFRP4 expression. Increased SFRP4 down-regulated the key gene β-catenin, the downstream effectors gene ccnd1 and fibronectin expression in canonical Wnt pathway at the same time. MeCP2 and DNA methylation may provide molecular mechanisms for canonical Wnt pathway activation in RA. Combination of 5-azadC and MeCP2 may be a promising treatment strategy for individuals with RA in which SFRP4 is inactivated.

Topics: Animals; Arthritis, Rheumatoid; Azacitidine; beta Catenin; Cell Proliferation; Cells, Cultured; Cyclin D1; Decitabine; DNA Methylation; Down-Regulation; Fibroblasts; Fibronectins; Male; Methyl-CpG-Binding Protein 2; Proto-Oncogene Proteins; Rats; Rats, Sprague-Dawley; RNA Interference; RNA, Messenger; RNA, Small Interfering; Synovial Membrane; Wnt Signaling Pathway

Recently, it was discovered that high mobility group box chromosomal protein 1 (HMGB1) acts as a potent pro-inflammatory cytokine that is released into the extracellular milieu. Signal transducer and activator of transcription (STAT) proteins play an important role in cytokine signaling. Some investigators have reported preferential activation of STAT1, and others have reported preferential activation of STAT3 in response to endogenous interleukin-6 (IL-6) in patients with rheumatoid arthritis. Here, we show that expression of the HMGB1 protein is increased in the articular tissues of collagen-induced arthritis (CIA) rats, especially in cytoplasm and extracellular, following synoviocyte proliferation and STAT1 activation. In vitro, recombined human HMGB1 induced RSC-364 cell proliferation, activated STAT1 phosphorylation, increased the expression of cyclin D1 and CDK4 protein, and decreased the expression of p21 protein. In summary, our study suggests that HMGB1 plays an important role of cytokine in the pathogenesis of RA, which possibly induces synovial cell proliferation by activating the STAT1 signal pathway.

Topics: Animals; Arthritis, Rheumatoid; Cell Line; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase 4; Endothelial Cells; HMGB1 Protein; Humans; Immunohistochemistry; Rats; Rats, Wistar; Signal Transduction; STAT1 Transcription Factor; Synovial Membrane

It is known that the cyclin-dependent kinase inhibitor (CDKI) gene p21(Cip1) suppresses rheumatoid inflammation by down-modulating type I interleukin-1 receptor (IL-1RI) expression and inhibiting JNK activity. The purpose of this study was to determine whether CDK activity directly modulates the production of inflammatory molecules in patients with rheumatoid arthritis (RA).. Genes for the CDKIs p16(INK4a) and p18(INK4c), a constitutively active form of retinoblastoma (RB) gene product, cyclin D1, and CDK-4, were transferred into RA synovial fibroblasts (RASFs). RASFs were also treated with a synthetic CDK-4/6 inhibitor (CDK4I). Levels of matrix metalloproteinase 3 (MMP-3), monocyte chemoattractant protein 1 (MCP-1), and IL-1RI expression were determined by Northern blotting, real-time polymerase chain reaction analysis, and enzyme-linked immunosorbent assay. CDKIs were immunoprecipitated to reveal their association with JNK.. Transfer of the p16(INK4a) and p18(INK4c) genes and CDK4I suppressed the production of MMP-3 and MCP-1. Unlike p21(Cip1), neither CDKI gene inhibited IL-1RI or JNK. The expression of MMP-3 was up-regulated when CDK-4 activity was augmented. This regulation functioned at the messenger RNA (mRNA) level in MMP-3, but not in MCP-1. Transfer of active RB suppressed the production of MMP-3 and MCP-1 without changing their mRNA levels.. CDK-4/6 modulated the production of MMP-3 and MCP-1. MMP-3 production was regulated primarily at the mRNA level in an RB-independent manner, whereas MCP-1 production was controlled posttranscriptionally by RB. These results show that cell cycle proteins are associated with control of mediators of inflammation through multiple pathways.

Topics: Arthritis, Rheumatoid; Cell Proliferation; Cells, Cultured; Chemokine CCL2; Cyclin D1; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Cyclin-Dependent Kinase Inhibitor p16; Cyclin-Dependent Kinase Inhibitor p18; Cyclin-Dependent Kinase Inhibitor p21; Fibroblasts; Gene Expression Regulation; Humans; MAP Kinase Kinase 4; Matrix Metalloproteinase 3; Receptors, Interleukin-1; Receptors, Interleukin-1 Type I; Retinoblastoma Protein; RNA, Messenger; Synovial Membrane

This report details the pulmonary pathologic findings in four patients with rheumatoid arthritis, who developed new onset of pulmonary signs and symptoms with alveolar infiltrates temporally related to the institution of etanercept therapy. Biopsy findings showed an interstitial and air space lymphohistiocytic infiltrate with non-necrotizing granulomas, in the setting of negative cultures and special stains for microorganisms. The association with etanercept therapy and granulomatous reactions is discussed along with the differential diagnosis.

Topics: Adult; Aged; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Antirheumatic Agents; Arthritis, Rheumatoid; CD3 Complex; CD5 Antigens; Cough; Cyclin D1; Diagnosis, Differential; Dyspnea; Etanercept; Female; Granuloma; Histiocytes; Humans; Immunoglobulin G; Immunohistochemistry; Leukosialin; Lung Diseases; Lymphocytes; Middle Aged; Receptors, Tumor Necrosis Factor; Sialoglycoproteins