The experience and reflections of GC labs as an independent clinical laboratory to the COVID-19 pandemic in South Korea.

BACKGROUND: Amid the COVID-19 pandemic, extensive testing was undertaken by independent clinical laboratories (ICLs), yet limited research exists on this matter. Drawing from Green Cross Laboratories (GC Labs)' pandemic response experience, this study seeks to offer insights for preparation for the next pandemic. METHODS: This retrospective study analyzed the outcomes of SARS-CoV-2 real-time reverse transcription polymerase chain reaction (SARS-CoV-2 rRT PCR) tests administered by GC Labs for COVID-19 diagnosis, upon request by different organizations, between February 2020 and April 2022. The distribution of institutions that requested the tests, the type of tests, and the positive rate were analyzed. We investigated resource allocation details. RESULTS: ICLs were responsible for conducting 85.6% of all tests carried out under South Korea's COVID-19 testing policy during the pandemic. The availability of free testing regardless of symptoms led to a significant increase in the use of pooled tests, which accounted for more than 80% of all tests conducted after August 2021. The gender and age distribution of COVID-19 cases nationwide and GC Labs' positive cases were similar. When we analyzed the positive rate by requesting organizations during the COVID-19 pandemic, despite an overall nationwide positivity rate of 35%, high-risk facilities exhibited a positivity rate of less than 5% by maintaining preemptive testing. The most notable increase in resources during the pandemic was seen in human resource input. CONCLUSIONS: South Korea's ICLs were able to conduct large volumes of testing during the COVID-19 pandemic because of their logistics and computer systems, scalable testing space, and trained testing personnel. They also had the flexibility to bring in additional resources to expand testing capacity because they are specialized testing organizations. Hence, ICLs could execute the pooled test that the government had introduced for extensive general population screening. The preemptive periodic testing of high-risk populations kept the positive rate much lower than in the general population. This study's findings will aid in refining mass testing-based policies for the next pandemic.

Serum adipokine levels in rheumatoid arthritis patients and their contributions to the resistance to treatment.

The aim of this study was to determine whether disease activity and the type of therapy differentially modulate serum adipokine levels in patients with rheumatoid arthritis (RA), and whether pre-therapy adipokine levels contribute to resistance to treatment. Fasting blood samples from 40 RA patients were obtained at baseline and six months following therapeutic treatment with disease-modifying antirheumatic drugs (DMARDs) and/or tumor necrosis factor (TNF)-α blockers. Serum levels of adiponectin, leptin, visfatin and resistin were measured by ELISA. Baseline adipokine levels did not exhibit a statistically significant difference when comparing patients with moderate and high disease activity, based on the disease activity score in 28 joints (DAS28). Of all the adipokines, only adiponectin was significantly increased in patients responding to DMARDs and/or TNF-α blocker therapy, based on the American College of Rheumatology 20% improvement criteria (ACR20) at six months (2,964±1,237 to 3,683±1,511 ng/ml, P<0.01). However, adiponectin levels in non-responders did not significantly increase (3,192±2,090 to 3,222±1,150 ng/ml). By contrast, there were no statistically significant changes in leptin, resistin or visfatin levels in either the responders or non-responders. Serum adipokine (adiponectin, leptin, visfatin, and resistin) levels in RA patients did not significantly change following therapy, with the exception of adiponectin. Adipokine levels may not contribute to therapeutic resistance to DMARDs and/or TNF-α blocking agents.

Effect of taurine chloramine on differentiation of human preadipocytes into adipocytes.

We investigated whether taurine chloramine (TauCl), which is -endogenously produced by immune cells such as macrophages that infiltrate adipose tissue, affects the differentiation of preadipocytes into adipocytes or modulates the expression of adipokines in adipocytes. To study the physiological effects of TauCl on human adipocyte differentiation and adipokine expression, preadipocytes were cultured under differentiation conditions for 14 days in the presence or the absence of TauCl. Differentiated adipocytes were also treated with TauCl in the presence or the absence of IL-1ß (1 ng/ml) for 7 days. The culture supernatants were analyzed for adipokines such as adiponectin, leptin, IL-6, and IL-8. At concentrations of 400-600 µM, TauCl significantly inhibited the differentiation of human preadipocytes into adipocytes in a dose-dependent manner. It did not induce the dedifferentiation of adipocytes or inhibit fat accumulation in adipocytes. Expression of major transcription factors of adipogenesis and adipocyte marker genes was decreased after treatment with TauCl, in agreement with its inhibition of -differentiation. These results suggest that TauCl may inhibit the differentiation of -preadipocytes into adipocytes. Thus, TauCl or more stable derivatives of TauCl could potentially be a safe drug therapy for obesity-related diseases.

Analgesic and anti-inflammatory effects in animal models of an ethanolic extract of Taheebo, the inner bark of Tabebuia avellanedae.

Taheebo, the purple inner bark of the Bignoniaceae tree Tabebuia avellanedae Lorentz ex Griseb, which is found in tropical rain forests in northeastern Brazil, has been used as a traditional medicine for various diseases for more than 1,500 years. In the current study, various animal models were used to demonstrate the analgesic and anti-inflammatory properties of its ethanolic extract, thereby investigating its potential as a therapeutic treatment for diseases with pain and inflammation. In the hot plate and writhing tests for the in vivo analgesic effect test of Taheebo, a 200 mg/kg dose of the extract induced a significant anti-nociceptive effect and increased the pain threshold by approximately 30% compared with the control. In vascular permeability and tetradecanoylphorbol acetate (TPA)­, arachidonic acid- and carrageenan-induced paw edema tests for anti-inflammatory effects, treatment with 200 mg/kg Taheebo led to significant anti-inflammatory effects and inhibited inflammation by 30-50% compared with the control. At 100 mg/kg, the extract decreased the levels of pain and inflammation in all tested models, but the degree of inhibition was not statistically significant. The results suggest that the ethanolic extract of the inner bark of Tabebuia avellanedae has the potential to be developed as a therapeutic or supportive drug against diseases with accompanying pain and inflammation, including osteoarthritis.

Association between serum thymosin ß4 levels of rheumatoid arthritis patients and disease activity and response to therapy.

The aim of this study was to evaluate whether thymosin ß4 (Tß4) levels are increased in the serum of rheumatoid arthritis (RA) patients, and if this increase is associated with RA disease activity and resistance to treatment. Blood samples from 40 patients with RA were collected at baseline and 6 months after starting treatment with disease-modifying antirheumatic drugs (DMARD) and/or tumor necrosis factor (TNF)-α blocker. Serum levels of Tß4 were measured by ELISA. Tß4 levels (mean ± standard deviation) in RA patients were significantly (approximately tenfold) higher than in healthy controls (577.4 ± 67.92 vs. 56.61 ± 5.72 ng/mL). Serum Tß4 levels in patients with severe disease activity before therapy were slightly higher than in patients with moderate disease activity (662.4 ± 491.5 vs. 462.5 ± 305.3 ng/ml, P > 0.05). Tß4 levels were significantly associated with disease activity according to the 28-joint Disease Activity Score. The mean Tß4 level at baseline in the DMARD treatment group was significantly lower than in the DMARD + TNF-α blocker treatment group. Tß4 levels were increased in the serum of patients with RA and were positively associated with disease activity. Levels of Tß4 may also be relevant in determining or predicting resistance to RA treatment. Further studies are necessary to determine if Tß4 is an appropriate therapeutic target for controlling inflammation associated with RA.

Synergy between adiponectin and interleukin-1ß on the expression of interleukin-6, interleukin-8, and cyclooxygenase-2 in fibroblast-like synoviocytes.

To determine whether adiponectin may have synergistic effects in combination with the proinflammatory cytokine interleukin (IL)-1ß regarding the production of proinflammatory mediators during arthritic joint inflammation, synovial cells from rheumatoid arthritis (RA) patients were treated with adiponectin, IL-1ß, and their combination for 24 h. Culture supernatant was collected and analyzed by enzyme-linked immunosorbent assay for levels of IL-6, IL-8, prostaglandin E(2) (PGE(2)), vascular endothelial growth factor (VEGF), and matrix metalloproteinases (MMPs). Adiponectin-mediated intracellular signaling pathways were investigated to elucidate the molecular mechanisms underlying their synergy. The association of proinflammatory mediators with adiponectin was investigated in the synovial fluid of arthritis patients. Adiponectin functioned synergistically with IL-1ß to activate IL-6, IL-8, and PGE2 expression in RA fibroblast-like synoviocytes; Levels of VEGF, MMP-1, and MMP-13 were not synergistically stimulated. Adiponectin and IL-1ß each increased the expression of both adiponectin receptor 1 and IL-1 receptor 1. However, adiponectin and IL-1ß did not synergistically support the degradation of IκB-α or the nuclear translocation of NF-κB. Synergistically increased gene expression was significantly inhibited by MG132, an NF-κB inhibitor. Supporting the in vitro results, IL-6 and IL-8 levels were positively associated with adiponectin in synovial joint fluid from patients with RA, but not osteoarthritis (OA). In conclusion, adiponectin and IL-1ß may synergistically stimulate the production of proinflammatory mediators through unknown signaling pathways during arthritic joint inflammation. Adiponectin may be more important to the pathogenesis of RA than previously thought.

Positive rates of 2009 novel influenza A (H1N1) was high in school-aged individuals: significance in pandemic control.

In this study, data from a pandemic H1N1 outbreak in Korea were analyzed according to time, geography (districts), and age. A total of 252,271 samples collected nationwide were referred to the Greencross Reference Laboratory from June 2009 to February 2010 for H1N1 confirmation testing. Of these samples, 105,300 (41.7%) were H1N1-positive. With time, positivity was highest (57.0%) from October 26 - November 1 (4 weeks after Chuseok). The positive rates among districts show the highest value in Ulsan City (63.1%) and the lowest in Gyeongnam Province (32.8%). The positive rates for ages 0-2, 3-5, 6-11, 12-17, 18-20, 21-30, 31-40, 41-50, 51-60, and > 60 yr were 17.0%, 33.1%, 56.2%, 55.5%, 55.3%, 41.5%, 28.2%, 30.5%, 31.1%, and 16.8%, respectively, indirectly indicating propagation of H1N1 through schools. Pandemic control should involve school-targeted strategies.

Effects of the pro-inflammatory milieu on the dedifferentiation of cultured fibroblast-like synoviocytes.

The aim of this study was to determine whether the inflammatory milieu and/or hypoxia induces the dedifferentiation of synovial cells into mesenchymal stem-like cells, which may contribute to the tumor-like growth of synovial cells. Expression of mesenchymal stem cell markers (CD24, CD44, CD90, CD106, CD146 and Stro-1) was compared among cultured fibroblast-like synoviocytes (FLSs) from patients with rheumatoid arthritis (RA) or osteoarthritis (OA), bone marrow mesenchymal stem cells (BM MSCs) and normal dermal fibroblasts. After the cells were stimulated with pro-inflammatory cytokines for 3 days under hypoxia or normoxia, the stem cell markers were analyzed by FACS. CD44 and CD90 were expressed constitutively in all four cell types. Only the BM MSCs strongly expressed CD146. The expression of stem cell markers was similar between FLSs from RA and those from OA patients. In addition, the expression levels in FLSs were similar to those in normal dermal fibroblasts. The stimulation of FLSs and dermal fibroblasts with IL-1ß or a mixture of cytokines under hypoxia did not induce a marked change in the expression of stem cell markers. These results indirectly suggest that the pro-inflammatory milieu may be not sufficient to induce the dedifferentiation of FLSs in arthritic joints.

Implication of MMP-9 and urokinase plasminogen activator (uPA) in the activation of pro-matrix metalloproteinase (MMP)-13.

We examined whether the expression and activation of pro-matrix metalloproteinase (MMP)-1 varies from that of pro-MMP-13 in the joint fluid of osteoarthritis (OA) and rheumatoid arthritis (RA) patients. To do this, joint fluid was collected from 34 RA and 34 OA patients. The collagenase (pro-MMP-1 and MMP-13, total MMP-1, and MMP-13), gelatinase (total MMP-2 and MMP-9), stromelysin (total MMP-3), matrilysin (total MMP-7), uPA, and tissue inhibitor of MMP (TIMP) levels were measured by ELISA. The level of total MMP-1 in RA joint fluids was similar to that of the OA joint fluid. In contrast, the level of total MMP-13 in the RA group was significantly higher than that of the OA group. Among various MMPs (MMP-2, MMP-3, MMP-7, and MMP-9), only MMP-9 was strongly associated with total MMP-13 in both RA and OA. The level of uPA was also strongly associated with MMP-13 in RA but not OA, while the level of TIMP-1 and TIMP-2 was not significantly different between RA and OA. In conclusion, MMP-9 and uPA might be involved in the activation of pro-MMP-13 through unknown mechanisms in arthritic diseases.

Arthritic disease is more severe in older rats in a kaolin/carrageenan-induced arthritis model.

This study examined in an arthritis animal model whether elderly onset rheumatoid arthritis (EORA) is a more severe disease than younger onset rheumatoid arthritis. Arthritis was induced by injecting 5% kaolin/carrageenan into the left tibiotarsal ankles of 18-month-old and 4-week-old rats. Various parameters were measured to evaluate the arthritic progression of kaolin/carrageenan-induced arthritis in the rats. Immunohistochemical staining of arthritic joints was performed to determine the degree of inflammation in old and young rats. Measurements of ankle volume and thickness, arthritic index, number of squeaks, and the paw pressure test showed the 18-month-old rats had more severe disease than the young rats in a kaolin/carrageenan-induced arthritis model. The degree of inflammation and MMP-1 expression of arthritic joints in old rats was significantly higher than that of young rats based on histological evaluation with hematoxylin and eosin (H&E) staining and immunochemistry. More severe disease symptoms were found in old rats with EORA, but the molecular mechanisms still remain to be elucidated. Understanding the molecular mechanisms will be helpful to develop clinical protocols to efficiently treat patients with EORA, which is difficult to control with current protocols.

Increased expression of IL-1 receptors in response to IL-1ß may produce more IL-6, IL-8, VEGF, and PGE2 in senescent synovial cells induced in vitro than in presenescent cells.

Primary synovial cells with high passage number demonstrate increased production of proinflammatory mediators in response to inflammatory stimuli compared with cells with low passage number. This study used synovial cells to learn how different numbers of serial subculture passages affect the production of proinflammatory mediators in response to interleukin (IL)-1ß. Synovial cells were serially subcultured in flasks until passage 7. During cell passage, synovial cells were treated with IL-1ß for 24 h. Levels of proinflammatory mediators were analyzed by ELISA, real-time PCR, and Western blot. Synovial cells at passage 7 had elongated morphology and higher activity of ß-galactosidase, a marker of senescence, than those at passage 3. Production of IL-6, IL-8, vascular endothelial growth factor (VEGF), and prostaglandin E2 (PGE(2)) in response to IL-1ß was significantly increased in cells at passage 7 compared with passage 3. To evaluate the mechanism of this different response, IL-1 receptor expression was studied in cells stimulated with IL-1ß. Compared with cells at passage 3, cells at passage 7 had stronger expression of IL-1 receptors 1 and 2, as well as significantly increased expression of both receptors, in response to IL-1ß. This finding suggests that differential production in response to inflammatory stimuli associated with cell passages should be considered when in vitro experiments are used to evaluate the production levels of proinflammatory mediators.

WIN-34B May Have Analgesic and Anti-Inflammatory Effects by Reducing the Production of Pro-Inflammatory Mediators in Cells via Inhibition of IκB Signaling Pathways.

WIN-34B showed analgesic and anti-inflammatory effects in various animal models of pain and osteoarthritis. However, the molecular mechanism by which WIN-34B inhibits pain and inflammation in vivo remains to be elucidated. We investigated the molecular mechanisms of the actions of WIN-34B using various in vitro models using fibroblast-like synoviocytes from patients with rheumatoid arthritis (RA FLSs), RAW264.7 cells and peritoneal macrophages. WIN-34B inhibited the level of IL-6, PGE2, and MMP-13 in IL-1ß-stimulated RA FLSs in a dose-dependent manner. The mRNA levels were also inhibited by WIN-34B. The level of PGE2, NO, IL-1ß, and TNF-α were inhibited by WIN-34B at different concentrations in LPS-stimulated RAW264.7 cells. The production of NO and PGE2 was inhibited by WIN-34B in a dose-dependent manner in LPS-stimulated peritoneal macrophages. All of these effects were comparable to the positive control, celecoxib or indomethacin. IκB signaling pathways were inhibited by WIN-34B, and the migration of NF-κB into the nucleus was inhibited, which is consistent with the degradation of IκB-α. Taken together, the results suggest that WIN-34B has potential as a therapeutic drug to reduce pain and inflammation by inhibiting the production of pro-inflammatory mediators.

Expression levels and association of gelatinases MMP-2 and MMP-9 and collagenases MMP-1 and MMP-13 with VEGF in synovial fluid of patients with arthritis.

This study was performed to provide evidence, albeit indirectly, as to which matrix metalloproteinases (MMPs), among the gelatinases MMP-2 and MMP-9 and the collagenases MMP-1 and MMP-13, play a more proactive role in the angiogenic process in arthritic joint. Joint fluid was collected from 33 patients with rhuematoid arthritis (RA) and osteoarthritis (OA), and protein (MMPs and vascular endothelial growth factor (VEGF)) levels were measured by ELISA, and the association of MMPs with VEGF was evaluated in joint fluid of patients with RA or OA. The levels of collagenases (total MMP-1 and total MMP-13) and gelatinases (total MMP-2 and total MMP-9) in RA joint fluid were significantly higher than those in OA fluid. Total MMP-9 levels were significantly associated with VEGF levels in RA fluids, but not in OA fluid, while total MMP-13 levels were strongly associated with VEGF levels in both RA and OA fluid. However, total MMP-2 and total MMP-1 levels were not associated with VEGF levels in either RA or OA joint fluid. Our results indirectly suggest that in RA and OA, MMP-9 and MMP-13 may play a more important role in angiogenesis than MMP-2 and MMP-1.

Groundwater contamination and natural attenuation capacity at a petroleum spilled facility in Korea.

As a remedial option, the natural attenuation capacity of a petroleum contaminated groundwater at a military facility was examined. Hydrogeological conditions, such as high water level, permeable uppermost layer and frequent heavy rainfall, were favorable to natural attenuation at this site. The changes in the concentrations of electron acceptors and donors, as well as the relevant hydrochemical conditions, indicated the occurrence of aerobic respiration, denitrification, iron reduction, manganese reduction and sulfate reduction. The calculated BTEX expressed biodegradation capacity ranged between 20.52 and 33.67 mg/L, which appeared effective for the reduction of the contaminants levels. The contribution of each electron accepting process to the total biodegradation was in the order: denitrification > iron reduction > sulfate reduction > aerobic respiration > manganese reduction. The BTEX and benzene point attenuation rates were 0.0058-0.0064 and 0.0005-0.0032 day(-1), respectively, and the remediation time was 0.7-1.2 and 2.5-30 years, respectively. The BTEX and benzene bulk attenuation rates were 8.69 x 10(-4) and 1.05 x 10(-3) day(-1), respectively, and the remediation times for BTEX and benzene were 7.2 and 17.5 years, respectively. However, most of the natural attenuation occurring in this site can be attributed to dilution and dispersion. Consequently, the biodegradation and natural attenuation capacities were good enough to lower the contaminants levels, but their rates appeared to be insufficient to reach the remediation goal within a reasonable time frame. Therefore, some active remedial measures would be required.

Effect of taurine chloramine on the production of matrix metalloproteinases (MMPs) in adiponectin- or IL-1beta-stimulated fibroblast-like synoviocytes.

BACKGROUND: Adiponectin greatly stimulated the expression of matrix metalloproteinases (MMPs) in fibroblast-like synoviocytes (FLSs) as did IL-1beta. We wondered whether taurine chloramine (TauCl) inhibits the production of MMPs stimulated by adiponectin in the same pattern as by IL-1beta stimulation in vitro METHODS: Synovial cells from rheumatoid arthritis (RA) patients were treated with adiponectin or interleukin (IL)-1beta for 24 hr in the presence or absence of TauCl. The culture supernatant was collected and the levels of MMPs were measured by enzyme-linked immunosorbent assay (ELISA). The IkappaB signaling pathways stimulated by adiponectin were studied and the levels of NF-kappaB in the nuclei of the cells were analyzed by ELISA. RESULTS: TauCl (600 microM) inhibited MMP-13, but not MMP-1, expression in IL-1beta-stimulated RA FLSs. However, TauCl at the same concentration significantly inhibited the production of both adiponectin-stimulated MMP-1 and MMP-13 expression. TauCl inhibited the degradation of IkappaB-alpha stimulated by adiponectin, but not by IL-1beta. Similarly, the level of NF-kappaB in the nucleus was increased by adiponectin stimulation and was inhibited by 600 microM TauCl. However, the levels of NF-kappaB increased by IL-1beta stimulation were not inhibited by 600 microM TauCl. CONCLUSIONS: TauCl more effectively inhibited MMPs expression induced by adiponectin than that by IL-1beta in RA FLS, suggesting that TauCl plays an important role in down-regulating the expression of MMPs in arthritic joints.

Fetal bovine serum requirement for pyrrolidine dithiocarbamate-induced apoptotic cell death of MCF-7 breast tumor cells.

Pyrrolidine dithiocarbamate (PDTC) can form a complex with metal ions and then act as a proteasome inhibitor, which leads to tumor cell apoptosis, and could therefore be developed as an anticancer agent. In our efforts to find factors that induce PDTC-mediated apoptosis of tumor cells, the effect of serum concentration on the apoptotic activity of PDTC was investigated. PDTC could not induce MCF-7 breast tumor cell death in serum-free media but significantly induced cell death in a dose-dependent manner at concentrations of ≥25 µM in media containing 10% fetal bovine serum. PDTC-mediated cell death was also dependent on serum concentration. PDTC-mediated cell death occurred through apoptosis. Similar to that in normal FBS, PDTC-mediated apoptotic cell death was also induced in media containing dialyzed FBS, indicating that PDTC-mediated apoptosis does not require metal ions or salts, but rather proteins in fetal bovine serum. In addition, differential apoptotic effects of PDTC were not observed with inhibitors of NF-κB activation such as N-acetylcysteine (NAC), Fenofibrate and carbobenzoxyl-l-leucyl-l-leucyl-l-leucinal (MG132) or with the metal-binding agent, 5-chloro-7-iodo-8-hydroxyquinoline (Clioquinol). These results indicate that serum is required for PDTC-mediated apoptosis and that zinc-binding compounds such as PDTC, N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) and Clioquinol may each have their own mechanisms by which they induce tumor cell death, even though they are all classified as zinc-binding compounds.

Differential effect of IL-1ß and TNFα on the production of IL-6, IL-8 and PGE2 in fibroblast-like synoviocytes and THP-1 macrophages.

Inflammation in the joint of rheumatoid arthritis is a complex immune reaction facilitated by various factors, such as cytokines, cells and hypoxia. Thus, we evaluated their relative capacity to produce proinflammatory mediators in response to IL-1beta, TNF-alpha or IL-17 under hypoxia or normoxia in fibroblast-like synoviocytes (FLSs) and macrophages. The level of IL-6 expression was strongly increased in both FLSs and THP-1 macrophages in response to IL-1beta and TNF-alpha, but the level by TNF-alpha was less than that by IL-1beta. In contrast, the expression of IL-8 in both cell types was strongly stimulated by both IL-1beta and TNF-alpha. In FLSs, PGE(2) production increased only in response to IL-1beta; and no effect was observed in THP-1 cells and TNF-alpha-stimulated FLSs. In addition, the production by IL-17 was extremely low when compared with those induced by IL-1beta or TNF-alpha in FLSs and THP-1 cells. Hypoxia (2% O(2)) decreased IL-1beta-stimulated production of PGE(2), even though it increased the expression of mRNA and protein of COX-2. These results suggest that IL-1beta and TNF-alpha differentially regulate gene expression in FLSs and macrophages under hypoxia or normoxia.

Adiponectin may contribute to synovitis and joint destruction in rheumatoid arthritis by stimulating vascular endothelial growth factor, matrix metalloproteinase-1, and matrix metalloproteinase-13 expression in fibroblast-like synoviocytes more than proinflammatory mediators.

INTRODUCTION: The role of adiponectin in the pathogenesis of arthritis is still controversial. This study was performed to examine whether adiponectin is involved in joint inflammation and destruction in rheumatoid arthritis (RA) in relation to the expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs). METHODS: Synovial cells from RA patients were treated with adiponectin or interleukin (IL)-1beta for 24 hours. The culture supernatant was collected and analyzed for the levels of IL-6, IL-8, prostaglandin E2 (PGE2), VEGF, and MMPs by enzyme-linked immunosorbent assay. The levels of adiponectin, VEGF, MMP-1, and MMP-13 in the joint fluids from 30 RA or osteoarthritis (OA) patients were also measured. RESULTS: Adiponectin at the concentration of 10 microg/mL stimulated the production of IL-6, IL-8, and PGE2 in RA fibroblast-like synoviocytes (FLSs), although the level of these was much lower than with 1 ng/mL IL-1beta. However, adiponectin stimulated the production of VEGF, MMP-1, and MMP-13 at the same level as IL-1beta. In addition, the level of adiponectin and MMP-1 in the joint fluid of RA patients was significantly higher than in OA patients. Adiponectin was positively correlated with VEGF in RA patients but not in OA patients, while the level of MMPs in joint fluid was not correlated with adiponectin in either RA or OA patients. CONCLUSIONS: Adiponectin may play a significant role in the pathogenesis of RA by stimulating the production of VEGF and MMPs in FLSs, leading to joint inflammation and destruction, respectively.

Pyrrolidine dithiocarbamate, a NF-kappaB inhibitor, upregulates MMP-1 and MMP-13 in IL-1beta-stimulated rheumatoid arthritis fibroblast-like synoviocytes.

Activated NF-kappaB plays an important role in the expression of matrix metalloproteinase (MMP)-1 and MMP-13 in rheumatoid arthritis and osteoarthritis. The objective of this study was to determine the effects of the NF-kappaB inhibitor pyrrolidine dithiocarbamate (PDTC) on the expression of MMPs in IL-1beta-stimulated fibroblast-like synoviocytes (FLSs) of rheumatoid arthritis patients. FLSs were treated with IL-1beta (10 ng/ml) for 24 h in the presence or absence of PDTC. The level of MMP-1 and MMP-13 increased in response to PDTC in time- and dose-dependent manners in IL-1beta-stimulated FLSs; the expressions of IL-6 and vascular endothelial growth factor (VEGF) decreased in a PDTC concentration-dependent manner. However, PDTC-mediated repression of IL-6 and VEGF expression was not observed in TNF-alpha-stimulated rheumatoid arthritis FLSs. In contrast, other NF-kappaB inhibitors, such as fenofibrate, N-acetylcysteine and MG132, decreased MMP expression in IL-1beta-stimulated FLSs. The stimulatory effect of PDTC on MMP expression was not mimicked by specific inhibitors of the mitogen-activated protein kinase (MAPK) signaling pathway. Treatments with 100 muM PDTC did not inhibit the phosphorylation of p-ERK1/2, p-P38, and p-JNK, or the transnuclear migration of NF-kappaB through degradation of IkappaB-alpha in IL-1beta-stimulated FLSs. These results suggest that the increase of MMP expression may occur in a stimuli-specific manner or by an NF-kappaB independent mechanism. Therefore, therapeutic NF-kappaB inhibitors should be thoroughly studied before their clinical use in treating rheumatoid arthritis, as undesirable genes may be upregulated through unknown mechanisms, possibly resulting in worse symptoms.

Anti-inflammatory and antiarthritic effects of piperine in human interleukin 1beta-stimulated fibroblast-like synoviocytes and in rat arthritis models.

INTRODUCTION: The objective of this study was to determine the anti-inflammatory, nociceptive, and antiarthritic effects of piperine, the active phenolic component in black pepper extract. METHODS: The in vitro anti-inflammatory activity of piperine was tested on interleukin 1beta (IL1beta)-stimulated fibroblast-like synoviocytes derived form patients with rheumatoid arthritis. The levels of IL6, matrix metalloproteinase (MMPs), cyclo-oxygenase 2 (COX-2), and prostaglandin E2 (PGE2) were investigated by ELISA and RT-PCR analysis. The analgesic and antiarthritic activities of piperine were investigated on rat models of carrageenan-induced acute paw pain and arthritis. The former were evaluated with a paw pressure test, and the latter by measuring the squeaking score, paw volume, and weight distribution ratio. Piperine was administrated orally to rats at 20 and 100 mg/kg/day for 8 days. RESULTS: Piperine inhibited the expression of IL6 and MMP13 and reduced the production of PGE2 in a dose dependant manner at concentrations of 10 to 100 microg/ml. In particular, the production of PGE2 was significantly inhibited even at 10 microg/ml of piperine. Piperine inhibited the migration of activator protein 1 (AP-1), but not nuclear factor (NF)kappaB, into the nucleus in IL1beta-treated synoviocytes. In rats, piperine significantly reduced nociceptive and arthritic symptoms at days 8 and 4, respectively. Histological staining showed that piperine significantly reduced the inflammatory area in the ankle joints. CONCLUSIONS: These results suggest that piperine has anti-inflammatory, antinociceptive, and antiarthritic effects in an arthritis animal model. Thus, piperine should be further studied with regard to use either as a pharmaceutical or as a dietary supplement for the treatment of arthritis.