MKP-1 Deficiency Exacerbates Skin Fibrosis in a Mouse Model of Scleroderma.

Scleroderma is a chronic fibrotic disease, where proinflammatory and profibrotic events precede collagen accumulation. MKP-1 [mitogen-activated protein kinase (MAPK) phosphatase-1] downregulates inflammatory MAPK pathways suppressing inflammation. MKP-1 also supports Th1 polarization, which could shift Th1/Th2 balance away from profibrotic Th2 profile prevalent in scleroderma. In the present study, we investigated the potential protective role of MKP-1 in scleroderma. We utilized bleomycin-induced dermal fibrosis model as a well-characterized experimental model of scleroderma. Dermal fibrosis and collagen deposition as well as the expression of inflammatory and profibrotic mediators were analyzed in the skin samples. Bleomycin-induced dermal thickness and lipodystrophy were increased in MKP-1-deficient mice. MKP-1 deficiency enhanced collagen accumulation and increased expression of collagens, 1A1 and 3A1, in the dermis. Bleomycin-treated skin from MKP-1-deficient mice also showed enhanced expression of inflammatory and profibrotic factors IL-6, TGF-ß1, fibronectin-1 and YKL-40, and chemokines MCP-1, MIP-1α and MIP-2, as compared to wild-type mice. The results show, for the first time, that MKP-1 protects from bleomycin-induced dermal fibrosis, suggesting that MKP-1 favorably modifies inflammation and fibrotic processes that drive the pathogenesis of scleroderma. Compounds enhancing the expression or activity of MKP-1 could thus prevent fibrotic processes in scleroderma and possess potential as a novel immunomodulative drug.

Human Osteoarthritic Chondrocytes Express Nineteen Different TRP-Genes-TRPA1 and TRPM8 as Potential Drug Targets.

Transient receptor potential (TRP) ion channels are expressed in neuronal and some non-neuronal cells and are involved particularly in pain and thermosensation. We previously showed that TRPA1 is functionally expressed in human osteoarthritic (OA) chondrocytes and mediates inflammation, cartilage degradation, and pain in monosodium-iodoacetate-induced experimental OA. In the present study, we explored the expression of TRP-channels in primary human OA chondrocytes and investigated whether drugs used in the treatment of OA, ibuprofen and glucocorticoids, have effects on TRP-channel expression. OA cartilage was obtained from knee replacement surgery and chondrocytes were isolated with enzyme digestion. NGS analysis showed the expression of 19 TRP-genes in OA chondrocytes, with TRPM7, TRPV4, TRPC1, and TRPM8 having the highest counts in unstimulated cells. These results were verified with RT-PCR in samples from a different group of patients. Interleukin-1ß (IL-1ß) significantly increased TRPA1 expression, while TRPM8 and TRPC1 expression was decreased, and TRPM7 and TRPV4 expression remained unaffected. Furthermore, dexamethasone attenuated the effect of IL-1ß on TRPA1 and TRPM8 expression. The TRPM8 and TRPA1 agonist menthol increased the expression of the cartilage-degrading enzymes MMP-1, MMP-3, and MMP-13 and the inflammatory factors iNOS and IL-6 in OA chondrocytes. In conclusion, human OA chondrocytes express 19 different TRP-genes, of which the significant TRPM8 expression is a novel finding. Dexamethasone attenuated IL-1ß-induced TRPA1 expression. Interestingly, the TRPM8 and TRPA1 agonist menthol increased MMP expression. These results support the concept of TRPA1 and TRMP8 as potential novel drug targets in arthritis.

Pinosylvin Shifts Macrophage Polarization to Support Resolution of Inflammation.

Pinosylvin is a natural stilbenoid found particularly in Scots pine. Stilbenoids are a group of phenolic compounds identified as protective agents against pathogens for many plants. Stilbenoids also possess health-promoting properties in humans; for instance, they are anti-inflammatory through their suppressing action on proinflammatory M1-type macrophage activation. Macrophages respond to environmental changes by polarizing towards proinflammatory M1 phenotype in infection and inflammatory diseases, or towards anti-inflammatory M2 phenotype, mediating resolution of inflammation and repair. In the present study, we investigated the effects of pinosylvin on M2-type macrophage activation, aiming to test the hypothesis that pinosylvin could polarize macrophages from M1 to M2 phenotype to support resolution of inflammation. We used lipopolysaccharide (LPS) to induce M1 phenotype and interleukin-4 (IL-4) to induce M2 phenotype in J774 murine and U937 human macrophages, and we measured expression of M1 and M2-markers. Interestingly, along with inhibiting the expression of M1-type markers, pinosylvin had an enhancing effect on the M2-type activation, shown as an increased expression of arginase-1 (Arg-1) and mannose receptor C type 1 (MRC1) in murine macrophages, and C-C motif chemokine ligands 17 and 26 (CCL17 and CCL26) in human macrophages. In IL-4-treated macrophages, pinosylvin enhanced PPAR-γ expression but had no effect on STAT6 phosphorylation. The results show, for the first time, that pinosylvin shifts macrophage polarization from the pro-inflammatory M1 phenotype towards M2 phenotype, supporting resolution of inflammation and repair.

Metabolic Syndrome, Disease Activity, and Adipokines in Patients With Newly Diagnosed Inflammatory Joint Diseases.

OBJECTIVE: To investigate metabolic syndrome (MetS), disease activity, and adipokine levels among patients with rheumatoid arthritis (RA), spondyloarthritis (SpA), and undifferentiated arthritis (UA) at the time of diagnosis and after 1 year of follow-up. METHODS: Patients with inflammatory joint diseases participating in the Northern Savo 2010 population-based longitudinal epidemiological study were evaluated for components of MetS (by National Cholesterol Education Program's Adult Treatment Panel III) and clinical parameters of disease activity. The adipokines adiponectin, adipsin, resistin, and leptin were measured at baseline and after 1 year of treatment with disease-modifying antirheumatic drugs. RESULTS: Among 176 patients, MetS was detected in 42% of RA, 36% of SpA, and 51% of UA patients. Metabolic syndrome was associated with higher disease activity as measured by patient global assessment in RA and UA patients and increased pain in RA patients. Leptin levels were increased in patients with MetS, showing a linearly increasing trend with the number of components of MetS in SpA and UA, but not in RA. In RA patients, decrease in disease activity correlated with decrease in leptin levels. Resistin did not associate with MetS, but a decrease in resistin correlated with decrease in disease activity in RA and UA. In SpA, increased adiponectin level correlated with relief in disease activity, but not with MetS. CONCLUSIONS: Metabolic syndrome was common in patients with newly diagnosed arthritides and associated with higher disease activity and increased leptin levels. Resistin responded to treatment of arthritis in RA and UA, leptin in RA, and adiponectin in SpA.

Novel adipokine associated with OA: retinol binding protein 4 (RBP4) is produced by cartilage and is correlated with MMPs in osteoarthritis patients.

OBJECTIVE: Retinol binding protein 4 (RBP4) is a member of the lipocalin family and a vitamin A carrier in the blood. More recently, RBP4 has been described as an adipokine that is involved in insulin resistance and metabolic syndrome (MetS). As obesity, MetS and some adipokines contribute to the pathogenesis of osteoarthritis (OA), we investigated RBP4 in patients with OA. MATERIALS AND METHODS: Cartilage, synovial fluid and blood samples were collected from 100 OA patients undergoing total knee replacement surgery. Primary chondrocytes and cartilage tissue were cultured to measure the RBP4 expression. The concentrations of RBP4, other adipokines (adipsin, adiponectin, leptin and resistin) and biomarkers of OA (COMP, MMP-1, MMP-3 and YKL-40) were measured by immunoassay, and gene expression was measured by next-generation RNA sequencing. RESULTS: The OA cartilage samples released RBP4 into the culture medium, and the levels correlated positively with the expression of the adipokines adipsin, adiponectin, leptin and resistin. RBP4 was the most prominently expressed of these adipokines in the OA chondrocytes, and the expression of the RBP4 receptors STRA6 (stimulated by retinoic acid gene homologue 6) and TLR4 (Toll-like receptor 4) was also detected. Within the cartilage culture medium, RBP4 showed a positive correlation with MMP-1, MMP-3 and YKL-40. RBP4 was also present in the synovial fluid from the OA patients and correlated positively with the concentrations of RBP4 found in the plasma and the cartilage culture medium. Plasma RBP4 concentrations also showed a positive correlation with MMP-3 and adipsin. CONCLUSIONS: We show here, for the first time, that RBP4 is produced within OA joints and that it is associated with increased levels of adipokines and MMPs. The results suggest a role for RBP4 in the pathogenesis of OA and as a possible target for the disease-modifying drugs for the treatment of OA.

Bioactive Properties of the Aqueous Extracts of Endophytic Fungi Associated with Scots Pine (Pinus sylvestris) Roots.

Despite the continuing interest in various plant and natural products, only a small portion of the biologically active compounds from nature has been discovered and exploited. In this study, antioxidant and antibacterial properties of aqueous fractions of three endophytic fungi isolated from the roots of 8-year-old Scots pines (Pinus sylvestris) growing on a drained peatland were investigated. The endophytic fungi species were Acephala applanata, Phialocephala fortinii, and Humicolopsis cephalosporioides/Coniochaeta mutabilis. The bioactivities were examined using hydrogen peroxide scavenging and oxygen radical absorbance capacity tests as well as sensitive Escherichia coli-based biosensors, which produce a luminescent signal in the presence of substances with oxidative or genotoxic properties. In addition, cell models for Parkinson's disease, age-related macular degeneration, and osteoarthritis were used to evaluate the potential for pharmaceutical applications. The aqueous extracts of fungi and 19 out of 42 fractions were found to be active in one or more of the tests used. However, no activity was found in the age-related macular degeneration and osteoarthritis cell model tests. Additionally, bioactivity data was connected with metabolites putatively annotated, and out of 330 metabolites, 177 were interesting in view of the bioactivities investigated. A majority of these were peptides and all three fungal species shared a highly similar metabolome. We propose that Scots pine endophytic fungi are a rich source of interesting metabolites, and synergistic effects may cause the bioactivities, as they were found to vary after the fractionation process.

Transient Receptor Potential Ankyrin 1 (TRPA1) Is Involved in Upregulating Interleukin-6 Expression in Osteoarthritic Chondrocyte Models.

Transient receptor potential ankyrin 1 (TRPA1) is a membrane-bound ion channel found in neurons, where it mediates nociception and neurogenic inflammation. Recently, we have discovered that TRPA1 is also expressed in human osteoarthritic (OA) chondrocytes and downregulated by the anti-inflammatory drugs aurothiomalate and dexamethasone. We have also shown TRPA1 to mediate inflammation, pain, and cartilage degeneration in experimental osteoarthritis. In this study, we investigated the role of TRPA1 in joint inflammation, focusing on the pro-inflammatory cytokine interleukin-6 (IL-6). We utilized cartilage/chondrocytes from wild-type (WT) and TRPA1 knockout (KO) mice, along with primary chondrocytes from OA patients. The results show that TRPA1 regulates the synthesis of the OA-driving inflammatory cytokine IL-6 in chondrocytes. IL-6 was highly expressed in WT chondrocytes, and its expression, along with the expression of IL-6 family cytokines leukemia inhibitory factor (LIF) and IL-11, were significantly downregulated by TRPA1 deficiency. Furthermore, treatment with the TRPA1 antagonist significantly downregulated the expression of IL-6 in chondrocytes from WT mice and OA patients. The results suggest that TRPA1 is involved in the upregulation of IL-6 production in chondrocytes. These findings together with previous results on the expression and functions of TRPA1 in cellular and animal models point to the role of TRPA1 as a potential mediator and novel drug target in osteoarthritis.

IL-6 in Osteoarthritis: Effects of Pine Stilbenoids.

Interleukin-6 (IL-6) is involved in the pathogenesis of various inflammatory diseases, like rheumatoid arthritis (RA). In the present study, we investigated the role of IL-6 in osteoarthritis (OA) patients and the effects of the stilbenoids monomethyl pinosylvin and pinosylvin on the expression of the cartilage matrix components aggrecan and collagen II and the inflammatory cytokine IL-6 in human OA chondrocytes. Synovial fluid and plasma samples were obtained from 100 patients with severe OA [BMI 29.7 (8.3) kg/m², age 72 (14) years, median (IQR); 62/38 females/males] undergoing total knee replacement surgery. IL-6 and matrix metalloproteinase (MMP) concentrations in synovial fluid and plasma were measured by immunoassay. The effects of pinosylvin on the expression of IL-6, aggrecan, and collagen II were studied in primary cultures of human OA chondrocytes. IL-6 levels in synovial fluid from OA patients [119.8 (193.5) pg/mL, median (IQR)] were significantly increased as compared to the plasma levels [3.1 (2.7) pg/mL, median (IQR)] and IL-6 levels in synovial fluid were associated with MMPs and radiographic disease severity. Natural stilbenoids monomethyl pinosylvin and pinosylvin increased aggrecan expression and suppressed IL-6 production in OA chondrocytes. The results propose that IL-6 is produced within OA joints and has an important role in the pathogenesis of OA. Stilbenoid compounds monomethyl pinosylvin and pinosylvin appeared to have disease-modifying potential in OA chondrocytes.

Glycoprotein YKL-40 Levels in Plasma Are Associated with Fibrotic Changes on HRCT in Asbestos-Exposed Subjects.

YKL-40 is a chitinase-like glycoprotein produced by alternatively activated macrophages that are associated with wound healing and fibrosis. Asbestosis is a chronic asbestos-induced lung disease, in which injury of epithelial cells and activation of alveolar macrophages lead to enhanced collagen production and fibrosis. We studied if YKL-40 is related to inflammation, fibrosis, and/or lung function in subjects exposed to asbestosis. Venous blood samples were collected from 85 men with moderate or heavy occupational asbestos exposure and from 28 healthy, age-matched controls. Levels of plasma YKL-40, CRP, IL-6, adipsin, and MMP-9 were measured with enzyme-linked immunosorbent assay (ELISA). Plasma YKL-40 levels were significantly higher in subjects with asbestosis (n = 19) than in those with no fibrotic findings in HRCT following asbestos exposure (n = 66) or in unexposed healthy controls. In asbestos-exposed subjects, plasma YKL-40 correlated negatively with lung function capacity parameters FVC (Pearson's r -0.259, p = 0.018) and FEV1 (Pearson's r -0.240, p = 0.028) and positively with CRP (Spearman's rho 0.371, p < 0.001), IL-6 (Spearman's rho 0.314, p = 0.003), adipsin (Spearman's rho 0.459, p < 0.001), and MMP-9 (Spearman's rho 0.243, p = 0.025). The present finding suggests YKL-40 as a biomarker associated with fibrosis and inflammation in asbestos-exposed subjects.

Association of adiponectin and leptin with relative telomere length in seven independent cohorts including 11,448 participants.

Oxidative stress and inflammation are major contributors to accelerated age-related relative telomere length (RTL) shortening. Both conditions are strongly linked to leptin and adiponectin, the most prominent adipocyte-derived protein hormones. As high leptin levels and low levels of adiponectin have been implicated in inflammation, one expects adiponectin to be positively associated with RTL while leptin should be negatively associated. Within the ENGAGE consortium, we investigated the association of RTL with adiponectin and leptin in seven independent cohorts with a total of 11,448 participants. We performed partial correlation analysis on Z-transformed RTL and LN-transformed leptin/adiponectin, adjusting for age and sex. In extended models we adjusted for body mass index (BMI) and C-reactive protein (CRP). Adiponectin showed a borderline significant association with RTL. This appeared to be determined by a single study and when the outlier study was removed, this association disappeared. The association between RTL and leptin was highly significant (r = -0.05; p = 1.81 × 10(-7)). Additional adjustment for BMI or CRP did not change the results. Sex-stratified analysis revealed no difference between men and women. Our study suggests that high leptin levels are associated with short RTL.

Acute leukocyte, cytokine and adipocytokine responses to maximal and hypertrophic resistance exercise bouts.

The purpose of this study was to examine the acute immune response (circulating levels of leukocytes, cytokines and adipocytokines) to maximal resistance (MAX, 15 × 1RM) and hypertrophic resistance (HYP, 5 × 10RM) exercise bouts. Twelve healthy men (age = 28.2 ± 3.5 years, weight = 78.6 ± 10.4 kg, height 178.8 ± 5.0 cm, fat percentage = 16.5 ± 3.5 %) participated in the study. Blood was sampled before, immediately after and 15 and 30 min after exercise. Leukocytes (WBC) significantly increased immediately after HYP (p < 0.01), whereas in MAX, increases in WBC became significant after 30 min (p < 0.05). Lymphocytes increased only after HYP (p < 0.001), while MAX induced lymphopenia during recovery (p < 0.01). Monocyte chemoattractant protein-1 (MCP-1) decreased (p < 0.05) and interleukin-1 receptor antagonist (IL-1ra) increased after HYP, which were not observed after MAX. Adipsin and resistin decreased after both exercise bouts (p < 0.05), which suggest that heavy resistance exercise is at least transiently beneficial for adipocytokine profile. Immediate mechanical stress seemed similar as no differences in myoglobin response were observed. The higher magnitude of metabolic demand reflected in higher lactate response in HYP could be the reason for the significantly high responses in WBC, IL-1ra and decrease in MCP-1.

YKL-40 as a novel factor associated with inflammation and catabolic mechanisms in osteoarthritic joints.

YKL-40 is associated with tissue injury and inflammation, and consequently to diseases in which these mechanisms lead to tissue degradation, for example, asthma and rheumatoid arthritis. The purpose of the present study was to investigate if YKL-40 is also a significant factor in osteoarthritis (OA) by assessing associations of YKL-40 with mediators related to the pathogenesis of OA: cartilage destructing matrix metalloproteinases (MMPs) and proinflammatory cytokines interleukin-6 (IL-6) and interleukin-17 (IL-17). Cartilage, synovial fluid (SF), and plasma samples were obtained from 100 OA patients undergoing total knee replacement surgery. SF levels of YKL-40 (1027.9 ± 78.3 ng/mL) were considerably higher than plasma levels (67.2 ± 4.5 ng/mL) and correlated with YKL-40 released from cartilage samples obtained from the same patients (r = 0.37, P = 0.010), indicating that YKL-40 is produced by OA cartilage. Interestingly, YKL-40 concentrations in OA SF correlated positively with MMP-1 (r = 0.36, P = 0.014), MMP-3 (r = 0.46, P = 0.001), IL-6 (r = 0.57, P < 0.001), and IL-17 (r = 0.52, P = 0.010) levels. Moreover, IL-6 and IL-17 enhanced YKL-40 production in human primary chondrocyte cultures. The present study introduces YKL-40 as a cartilage-derived factor associated with mediators of inflammation and cartilage destruction involved in the pathogenesis of OA.

Adipokines NUCB2/nesfatin-1 and visfatin as novel inflammatory factors in chronic obstructive pulmonary disease.

COPD (chronic obstructive pulmonary disease) is a common lung disease characterized by airflow limitation and systemic inflammation. Recently, adipose tissue mediated inflammation has gathered increasing interest in the pathogenesis of the disease. In this study, we investigated the role of novel adipocytokines nesfatin-1 and visfatin in COPD by measuring if they are associated with the inflammatory activity, lung function, or symptoms. Plasma levels of NUCB2/nesfatin-1 and visfatin were measured together with IL-6, IL-8, TNF- α , and MMP-9, lung function, exhaled nitric oxide, and symptoms in 43 male patients with emphysematous COPD. The measurements were repeated in a subgroup of the patients after four weeks' treatment with inhaled fluticasone. Both visfatin and NUCB2/nesfatin-1 correlated positively with plasma levels of IL-6 (r = 0.341, P = 0.027 and rho = 0.401, P = 0.008, resp.) and TNF- α (r = 0.305, P = 0.052 and rho = 0.329, P = 0.033, resp.) and NUCB2/nesfatin-1 also with IL-8 (rho = 0.321, P = 0.036) in patients with COPD. Further, the plasma levels of visfatin correlated negatively with pulmonary diffusing capacity (r = -0.369, P = 0.016). Neither of the adipokines was affected by fluticasone treatment and they were not related to steroid-responsiveness. The present results introduce adipocytokines NUCB2/nesfatin-1 and visfatin as novel factors associated with systemic inflammation in COPD and suggest that visfatin may mediate impaired pulmonary diffusing capacity.

The glucocorticoid dexamethasone alleviates allergic inflammation through a mitogen-activated protein kinase phosphatase-1-dependent mechanism in mice.

Glucocorticoids are widely used in the treatment of allergic and inflammatory diseases. Glucocorticoids have a widespread action on gene expression resulting in their pharmacological actions and also an array of adverse effects which limit their clinical use. It remains, however, to be studied which target gene effects are essential for the anti-allergic activity of glucocorticoids. Mitogen-activated protein kinase phosphatase-1 (MKP-1) inhibits proinflammatory signalling by suppressing the activity of mitogen activated protein kinase (MAP kinase) pathways. MKP-1 is one of the anti-inflammatory genes whose expression is enhanced by glucocorticoids. In the present study, we aimed to investigate the role of MKP-1 in the therapeutic effects of the glucocorticoid dexamethasone in acute allergic reaction. The effects of dexamethasone were studied in wild-type and MKP-1 deficient mice. The mice were first sensitized to ovalbumin, and the allergic reaction was then induced by a subcutaneous ovalbumin injection in the hind paw. Inflammatory edema was quantified with plethysmometer and expression of inflammatory factors was measured by quantitative reverse transcription polymerase chain reaction (RT-PCR). Dexamethasone reduced the ovalbumin-induced paw edema at 1.5, 3 and 6 h time points in wild-type mice by 70%, 95% and 89%, respectively. The effect was largely abolished in MKP-1 deficient mice. Furthermore, dexamethasone significantly attenuated the expression of ovalbumin-induced inflammatory factors cyclooxygenase-2 (COX-2); inducible nitric oxide synthase (iNOS); interleukins (IL) 1ß, 6 and 13; C-C motif chemokine 11 (CCL-11); tumour necrosis factor (TNF) and thymic stromal lymphopoietin (TSLP) in wild-type mice by more than 40%. In contrast, in MKP-1 deficient mice dexamethasone had no effect or even enhanced the expression of these inflammatory factors. The results suggest that dexamethasone alleviates allergic inflammation through an MKP-1-dependent mechanism. The results also demonstrate MKP-1 as an important conveyor of the favourable glucocorticoid effects in ovalbumin-induced type I allergic reaction. Together with previous findings, the present study supports the concept of MKP-1 enhancing compounds as potential novel anti-inflammatory and anti-allergic drugs.

Inflammatory Glycoprotein YKL-40 Is Elevated after Coronary Artery Bypass Surgery and Correlates with Leukocyte Chemotaxis and Myocardial Injury, a Pilot Study.

The aim of the present study was to investigate the levels of YKL-40 during and after coronary artery bypass grafting surgery (CABG) and to establish possible connections between YKL-40 and markers of oxidative stress, inflammation, and myocardial injury. Patients undergoing elective CABG utilizing cardiopulmonary bypass (CPB) were recruited into the study. Blood samples were collected at the onset of anesthesia, during surgery and post-operatively. Levels of YKL-40, 8-isoprostane, interleukin-8 (IL-8), monocyte chemotactic protein-1 (MCP-1) and troponin T (TnT) were measured by immunoassay. YKL-40 levels increased significantly 24 h after CPB. Positive correlation was seen between post-operative TnT and YKL-40 levels (r = 0.457, p = 0.016) and, interestingly, baseline YKL-40 predicted post-operative TnT increase (r = 0.374, p = 0.050). There was also a clear association between YKL-40 and the chemotactic factors MCP-1 (r = 0.440, p = 0.028) and IL-8 (r = 0.484, p = 0.011) linking YKL-40 to cardiac inflammation and fibrosis following CABG. The present results show, for the first time, that YKL-40 is associated with myocardial injury and leukocyte-activating factors following coronary artery bypass surgery. YKL-40 may be a factor and/or biomarker of myocardial inflammation and injury and subsequent fibrosis following heart surgery.

Leptin enhances MMP-1, MMP-3 and MMP-13 production in human osteoarthritic cartilage and correlates with MMP-1 and MMP-3 in synovial fluid from OA patients.

OBJECTIVES: In the present study, we investigated the role of adipocytokine leptin in the pathogenesis of osteoarthritis (OA) by measuring its effects on matrix metalloproteinase (MMP) production in human OA cartilage. In addition, the correlations between leptin and MMP concentrations in synovial fluid from OA patients were studied. METHODS: Cartilage tissue obtained from leftover pieces of total knee replacement surgery from patients with OA was used in the experiments. Production of collagenases MMP-1, MMP-8 and MMP-13, and stromelysin-1 (MMP-3) in the cartilage was measured by immunoassay and the signalling pathways were explored by pharmacological means. In addition, synovial fluid samples were collected from 84 OA patients undergoing knee replacement surgery. The concentrations of leptin and MMPs in synovial fluid were measured by immunoassay. RESULTS: Leptin alone and in combination with IL-1ß enhanced production of MMP-1, MMP-3, and MMP-13 in human OA cartilage, while MMP-8 concentrations remained undetectable. The effects of leptin on MMP-1, MMP-3 and MMP-13 production were mediated through transcription factor NF-κß, and through protein kinase C and MAP kinase pathways. Interestingly, leptin concentrations in synovial fluid from OA patients correlated positively with MMP-3 (r=0.51, p<0.001) and MMP-1 (r=0.41, p<0.001) levels. CONCLUSIONS: To our knowledge, this is the first study to show that leptin up-regulates MMP-1 and MMP-3 production in human OA cartilage and correlates positively to MMP-1 and MMP-3 in synovial fluid from OA patients. The findings suggest that leptin has catabolic effects in OA joints by increasing MMP production in cartilage.

Infliximab treatment in patients with rheumatoid arthritis and spondyloarthropathies in one rheumatological center: two years' drug survival.

The aim of the present study was to determine the drug survival during 2 years' follow-up in patients (n = 104) with active rheumatoid arthritis (RA) or spondyloarthropathy (SpA) who were treated with infliximab as their first biological anti-rheumatic drug in a single rheumatological center. According to the national guidelines, infliximab was added to the treatment with combinations of traditional disease-modifying anti-rheumatic drugs (DMARD). Patients' records were analyzed at baseline and after 2 years of follow-up. The response to treatment was determined inadequate if the response was lower than ACR50 (American College of Rheumatology 50) in RA or the reduction of Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) was lower than 50% or 2 cm in SpA. Drug survival in infliximab-treated patients after 2 years was 40%, and among those who continued with the therapy the prednisolone dose has been reduced by 52%. Discontinuation rate was 60% during 2 years of follow-up, where 7% achieved remission and 22% of the patients were regarded as poor responders. As much as 24% of the patients discontinued due to an adverse event, mainly infections and hypersensitivity reactions. Two drug-related leukopenias were diagnosed. In the present study, infliximab therapy was initiated in RA or SpA patients who had active disease despite ongoing treatment with combinations of DMARDs. The drug survival with infliximab was 40% after 2 years of follow-up. During the 2-year follow-up, 60% discontinued infliximab treatment, mainly due to unsatisfactory or waning efficacy or a severe adverse event.

Widespread regulation of gene expression by glucocorticoids in chondrocytes from patients with osteoarthritis as determined by RNA-Seq.

BACKGROUND: Intra-articular glucocorticoid (GC) injections are widely used as a symptomatic treatment for osteoarthritis (OA). However, there are also concerns about their potentially harmful effects, and their detailed effects on chondrocyte phenotype remain poorly understood. METHODS: We studied the effects of dexamethasone on gene expression in OA chondrocytes with RNA-Seq. Chondrocytes were isolated from the cartilage from OA patients undergoing knee replacement surgery and cultured with or without dexamethasone for 24 h. Total RNA was isolated and sequenced, and functional analysis was performed against the Gene Ontology (GO) database. Results for selected genes were confirmed with RT-PCR. We also investigated genes linked to OA in recent genome-wide expression analysis (GWEA) studies. RESULTS: Dexamethasone increased the expression of 480 and reduced that of 755 genes with a fold change (FC) 2.0 or greater. Several genes associated with inflammation and cartilage anabolism/catabolism as well as lipid and carbohydrate metabolism were among the most strongly affected genes. In the GO analysis, genes involved in the extracellular matrix organization, cell proliferation and adhesion, inflammation, and collagen synthesis were enriched among the significantly affected genes. In network analysis, NGF, PI3KR1, and VCAM1 were identified as central genes among those most strongly affected by dexamethasone. CONCLUSIONS: This is the first study investigating the genome-wide effects of GCs on the gene expression in OA chondrocytes. In addition to clear anti-inflammatory and anticatabolic effects, GCs affect lipid and glucose metabolism in chondrocytes, an observation that might be particularly important in the metabolic phenotype of OA.

Association of rheumatoid arthritis disease activity and antibodies to periodontal bacteria with serum lipoprotein profile in drug naive patients.

Objective: We investigated lipid concentrations, particle sizes and antibodies binding to periodontal bacteria Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis and to malondialdehyde-acetaldehyde (MAA) modified low-density lipoprotein in immunoglobulin (Ig) class A, G and M among patients with newly diagnosed rheumatoid arthritis (RA) in a population-based cohort.Methods: Concentrations and sizes of lipoprotein particles analysed by proton nuclear magnetic resonance spectroscopy and antibody levels to MAA modified low-density lipoprotein were studied at baseline and after one-year of follow-up. Serum Ig A and G class antibodies to periodontal bacteria were determined at baseline.Results: Sixty-three patients were divided into tertiles according to disease activity by disease activity score with 28 joint count and erythrocyte sedimentation rate (ESR) (<3.9, 3.9-4.7, >4.7). Small low-density lipoprotein concentration was lowest in the tertile with the highest disease activity. In high-density lipoprotein, the concentrations of total, medium and small particles decreased with disease activity. The particle size in low-density lipoprotein associated with disease activity and the presence of antibodies to P. gingivalis. Ig G and M antibodies to MAA modified low-density lipoprotein correlated with disease activity. Inflammation associated changes faded by one year.Conclusions: Drug naive RA patients had proatherogenic changes in lipid profiles, but they were reversible, when inflammation diminished.Key messagesPatients with drug naive rheumatoid arthritis showed proatherogenic lipid profiles.Reversible changes in lipid profiles can be achieved as response to inflammation suppression.Active therapy aimed at remission is essential in all patients with rheumatoid arthritis.

Leptin enhances synthesis of proinflammatory mediators in human osteoarthritic cartilage--mediator role of NO in leptin-induced PGE2, IL-6, and IL-8 production.

Obesity is an important risk factor for osteoarthritis (OA) in weight-bearing joints, but also in hand joints, pointing to an obesity-related metabolic factor that influences on the pathogenesis of OA. Leptin is an adipokine regulating energy balance, and it has recently been related also to arthritis and inflammation as a proinflammatory factor. In the present paper, the effects of leptin on human OA cartilage were studied. Leptin alone or in combination with IL-1 enhanced the expression of iNOS and COX-2, and production of NO, PGE(2), IL-6, and IL-8. The results suggest that the effects of leptin are mediated through activation of transcription factor nuclear factor kappaB (NF-kappaB) and mitogen-activated protein kinase (MAPK) pathway c-Jun NH(2)-terminal kinase (JNK). Interestingly, inhibition of leptin-induced NO production with a selective iNOS inhibitor 1400 W inhibited also the production of IL-6, IL-8, and PGE(2), and this was reversed by exogenously added NO-donor SNAP, suggesting that the effects of leptin on IL-6, IL-8, and PGE(2) production are dependent on NO. These findings support the idea of leptin as a factor enhancing the production of proinflammatory factors in OA cartilage and as an agent contributing to the obesity-associated increased risk for osteoarthritis.