Search

In osteoarthritis (OA), chondrocytes in cartilage undergo phenotypic changes and senescence, restricting cartilage regeneration and favoring disease progression. Although senescence biomarker p16INK4a expression is known to induce aging by halting the cell cycle, therapeutic applications for p16INK4a targeting are limited. Here, we aimed to reduce cartilage damage and alleviate pain using p16INK4a nanoparticles in OA. The p16INK4a expression of human OA chondrocytes and synoviocytes from patients with knee OA was measured and the levels of p16INK4a, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and matrix metalloproteinase (MMP) 13 were examined. p16INK4a siRNA was encapsulated into poly (lactic-co-glycolic acid) (PLGA) nanoparticles and characterized. The partial medial meniscectomy (pMMx) model was performed for the OA model which was investigated by molecular analysis and behavioral tests. The expression of p16INK4a was increased in the synovium and articular cartilage from OA patients. p16INK4a siRNA-loaded PLGA nanoparticles (p16 si_NP) reduced the levels of TNF-α, IL-1β, and IL-6 especially in fibroblast-like synoviocytes (FLSs), and MMP13 in chondrocytes. Rhodamine-tagged NPs injected into the mouse knee joints were found mainly in the synovium. p16 si_NP injection in the pMMx model alleviated pain-associated behavior, and reduced cartilage damage and p16INK4a in the synovium, and MMP13, collagen X, and NITEGE in cartilage. The preferential reduction of p16INK4a in FLSs by the application of RNAi nanomedicine could contribute to the recovery of osteoarthritic cartilage and relieve pain, suggesting that p16INK4a may be a viable future therapeutic candidate.

Ixekizumab, a high-affinity interleukin-17A (IL-17A) monoclonal antibody, has previously shown efficacy in radiographic axial spondyloarthritis (also known as ankylosing spondylitis). We aimed to evaluate the efficacy and safety of ixekizumab, an IL-17 inhibitor, in non-radiographic axial spondyloarthritis. Here, we report the primary results of COAST-X.

Biological disease-modifying anti-rheumatic drugs (bDMARDs) are recommended for radiographic axial spondyloarthritis, otherwise known as ankylosing spondylitis, when conventional therapies are not effective. We report efficacy and safety data on ixekizumab, a high-affinity monoclonal antibody that selectively targets interleukin-17A (IL-17A), in patients with radiographic axial spondyloarthritis who have not previously been treated with bDMARDs.

The vasotocin receptor family is homologous to the mammalian vasopressin G-protein coupled receptor (GPCR) family. The vasotocin receptor 2 (VT2R) and 4 (VT4R) have recently been shown to play important role(s) in the neuroendocrine regulation of stress in birds. A homology-based structural model of VT4R of the domestic chicken, Gallus gallus, was built using the sophisticated SYBYL-X suite. The structure of VT4R built with and without extra- and intracellular unstructured loops showed a seven-helix transmembrane domain, which is a characteristic feature of GPCRs. Several agonists and antagonists were screened by molecular docking to map their potential binding sites on the structure of VT4R. Interestingly, the presence of the N-terminal, intracellular and extracellular loops and C-terminal amino acid sequences emerging from the transmembrane domains during molecular docking appeared to influence the binding interface of the peptide agonists and peptide/non-peptide antagonists on the VT4R. The presence of unstructured loops, however, did not affect the relative binding affinity ranking of the peptide antagonists to VT4R. In general, the natural ligand, arginine vasotocin and the peptide/non-peptide antagonists were observed to be more deeply buried in the receptor. Results of in vitroinhibition experiments, using cultured anterior pituitary cells, showed excellent agreement with the binding affinity of the antagonists predicted by molecular docking. The results of this study provide valuable clues for the rational design of novel pharmaceutical compounds capable of blocking or attenuating the stress response.

In humans, interleukin-1β (IL-1β) has been suggested as an essential cytokine for developing IL-17– or IL-17A–producing CD4+ T helper 17 (Th17) cells. However, little is known about the relationship of IL-1 receptor expression and Th17 cell differentiation. We report here the presence of 2 distinct CD4+ T-cell populations with and without expression of IL-1RI that correlates with the capacity to produce IL-17 in naive and memory CD4+ T cells of human peripheral blood. IL-1RI+ memory CD4+ T cells had increased gene expression of IL17, RORC, and IRF4 even before T-cell receptor triggering, indicating that the effect of IL-1β is programmed in these cells via IL-1RI. Although CD4+ T cells from umbilical cord blood did not express IL-1RI, the cytokines IL-7, IL-15, and transforming growth factor-β (TGF-β) up-regulated IL-1RI expression on naive CD4+ T cells, suggesting that IL-1RI+ naive CD4+ T cells develop in periphery. Furthermore, IL-17 production from the cytokine-treated naive CD4+ T cells was induced by IL-1β and this induction was blocked by IL-1R antagonist. These results indicate that human Th17 cell differentiation is regulated via differential expression of IL-1RI, which is controlled by IL-7 and IL-15.

Filaggrin is expressed in the cornified layer of epidermis and known to be one of the antigenic targets in rheumatoid arthritis. Although the citrulline residue in filaggrin is thought to be an antigenic determinant recognized by autoantibodies, the diagnostic sensitivity of synthetic citrullinated peptide is variable. To investigate the implication of anti-filaggrin antibodies recognizing uncitrullinated filaggrin in rheumatoid arthritis, we assayed antibody titers using unmodified recombinant filaggrin in the sera from 73 patients with rheumatoid arthritis, 150 patients with other connective tissue diseases and 70 normal controls. We also performed the correlation analysis between antibody titers and the clinical variables in patients with rheumatoid arthritis. Titers of IgG anti-filaggrin antibodies were significantly higher in rheumatoid arthritis patients compared to normal controls (P=0.02), but not in patients with osteoarthritis, ankylosing spondylitis or systemic lupus erythematosus. IgG anti-filaggrin antibodies were more frequently found in patients with rheumatoid arthritis compared to normal controls (12.3% vs 1.4% respectively, P=0.04). An anti-filaggrin antibody titer was correlated with visual analogue scale of pain, tender joint count, Ritchie articular index or C-reactive protein, but not with anti-nuclear antibody or rheumatoid factor. These results suggest that anti-filaggrin antibody recognizes the uncitrullinated filaggrin as an antigen and its titer correlates with clinical parameters, explaining the variable sensitivity of anti-filaggrin antibody test.

OBJECTIVE: To assess the frequency of juvenile onset ankylosing spondylitis (JAS) in Korean patients with AS and to differentiate the clinical characteristics of JAS from adult onset ankylosing spondylitis (AAS). METHODS: We studied 98 consecutive patients with AS who visited the rheumatology clinic of a tertiary referral center and compared clinical and radiographic features of JAS (n = 41) with those of AAS (n = 57). RESULTS: Median age at onset in JAS was 14 years (range 7-16) and in AAS 22 years (range 17-38) (p < 0.01). Patients with JAS at presentation showed fewer spinal symptoms and more frequent peripheral joint symptoms than those with AAS (41.5% vs 80.7% and 73.2% vs 36.8%, respectively; p < 0.01). Current cervical spine disease was more frequent in AAS (66.7% vs 43.9%; p = 0.02) and current knee disease in JAS (26.8% vs 8.8%; p = 0.02). Patients with JAS showed a shorter tragus-wall distance (mean +/- SD 10.6 +/- 1.7 vs 13.1 +/- 6.9 cm; p < 0.01), more mobility on the modified Schober test (5.7 +/- 2.0 vs 4.0 +/- 2.6 cm; p < 0.01) and chest expansion (4.4 +/- 1.7 vs 3.2 +/- 1.8 cm; p < 0.01), and a better forced vital capacity (75.1 +/- 14.1% vs 82.1 +/- 16.1% of predicted value; p = 0.03) than those with AAS. Totally ankylosed sacroiliitis and spinal syndesmophyte on radiographs were less frequent in JAS patients than in AAS (19.5% vs 47.4% and 17.1% vs 54.4%, respectively; p < 0.01). CONCLUSION: The frequency of JAS (41.3%) among Koreans was higher than that reported for Caucasians. General joint involvement pattern at disease onset in JAS was similar to previous reports. Our data suggest that clinically and radiographically JAS has a less severe spinal disease course than AAS.

Abstract: We assessed the prevalence and clinical features of psoriatic arthritis (PsA) in Korean patients with psoriasis. The prevalence of PsA in patients with psoriasis was 9%. Patients with PsA were older and had a longer duration of skin disease than those with psoriasis alone (median age, 40 vs 35 years, P = 0.03, and 15.3 vs 11.7 years, P = 0.04, respectively). Spondylitis was the most common pattern of PsA (50%). Nail change, dactylitis, and enthesopathy were observed in 36%, 15.4%, and 15.6% of patients with PsA, respectively. Increased erythrocyte sedimentation rate (ESR), antinuclear antibody, and radiological sacroiliitis were more frequent in patients with PsA than in those with uncomplicated psoriasis (25.8% vs 10.3%, P = 0.04; 37.9% vs 16.7%, P = 0.02; and 37.8% vs 1.1%, P < 0.01, respectively). The onset ages of psoriasis and arthritis in the spondylitis group were significantly lower than those in the non-spondylitis group (median age, 21.5 vs 31 years, P = 0.03, and 28.5 vs 43.5 years, P = 0.01, respectively). HLA-B27 was prevalent in 8% of patients with PsA.

Description

Poly(p-hydroxybenzoic acid) (PHB)–poly(ethylene terephthalate) (PET) 8/2 thermotropic liquid crystalline copolyester, poly(ethylene 2,6-naphthalate) (PEN), and PET were mechanically blended to pursue the liquid crystalline (LC) phase of ternary blends. The torque values of blends with increasing PHB content abruptly decreased above 40 wt % of PHB content because the melt viscosity of ternary blends dropped. Glass transition temperature and melting temperature of blends increased with increasing PHB content. The tensile strength and initial modulus of blends were low at 10 and 20 wt % PHB. However, the blends containing above 30 wt % PHB were improved with increasing PHB content due to the formation of fibrous structure. The blend of 20 wt % PHB formed irregularly dispersed spherical domains, and the blends of 30–40 wt % PHB showed LCP ellipsoidal domains and fibrils. In the polarized optical photographs, the blends of 40 wt % PHB showed pseudo LC phases. The degree of transesterification and randomness of blends were increased with blending time. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 70: 1065–1073, 1998

Background: Reactive oxygen species (ROS) regulate the migration and invasion of fibroblast-like synoviocytes (FLS), which are key effector cells in rheumatoid arthritis (RA) pathogenesis. Nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4) induces ROS generation and, consequently, enhances cell migration. Despite the important interrelationship between RA, FLS, and ROS, the effect of NOX4 on RA pathogenesis remains unclear. Methods: FLS isolated from RA (n= 5) and osteoarthritis (OA, n= 5) patients were stimulated with recombinant interleukin 17 (IL-17; 10 ng/ml) and tumor necrosis factor alpha (TNF-α; 10 ng/ml) for 1 h. Cell migration, invasion, adhesion molecule expression, vascular endothelial growth factor (VEGF) secretion, and ROS expression were examined. The mRNA and protein levels of NOX4 were analyzed by RT-qPCR and western blotting, respectively. The NOX4 inhibitor GLX351322 and NOX4 siRNA were used to inhibit NOX4 to probe the effect of NOX4 on these cellular processes. Results: Migration of RA FLS was increased 2.48-fold after stimulation with IL-17 and TNF-α, while no difference was observed for OA FLS. ROS expression increased in parallel with invasiveness of FLS following cytokine stimulation. When the expression of NOXwas examined, NOX4was significantly increased by 9.73-fold in RA FLS compared to unstimulated FLS. Following NOX4 inhibition, cytokine-induced vascular cell adhesion molecule 1 (VCAM1), VEGF, and migration and invasion capacity of RA FLS were markedly decreased to unstimulated levels. Conclusion: NOX4 is a key contributor to cytokine-enhanced migration and invasion via modulation of ROS, VCAM1, and VEGF in RA FLS.