CXC and CC chemokines induced in human renal epithelial cells by inflammatory cytokines

LncRNA: A Potential Target for Host-Directed Therapy of Candida Infection

Despite various drugs work against Candida, candidiasis represents clinical management challenges worldwide due to the rising incidence and recurrence rate, as well as epidemics, of new drug-resistant pathogens. Recent insights into interactions between Candida and hosts contribute to exploring novel therapeutic strategies, termed host-directed therapies (HDTs). HDTs are viable adjuncts with good efficacy for the existing standard antifungal regimens. However, HDTs induce other response unintendedly, thus requiring molecular targets with highly specificity. Long noncoding RNAs (lncRNAs) with highly specific expression patterns could affect biological processes, including the immune response. Herein, this review will summarize recent advances of HDTs based on the Candida–host interaction. Especially, the findings and application strategies of lncRNAs related to the host response are emphasized. We propose it is feasible to target lncRNAs to modulate the host defense during Candida infection, which provides a new perspective in identifying options of HDTs for candidiasis.

Chemokine Profiles Are Affected in Serum of Patients with Acute Rejection of Kidney Allograft

Kidney allograft transplantation improved the prognosis and quality of life of patients with end-stage renal diseases but the occurrence of acute rejection represents a limitation of the final outcome. Noninvasive biomarkers are needed as well as further advancements in the understanding of immune mechanisms of reaction to the allograft. Our study of 138 patients focused on one-year monitoring of serum concentrations of 12 chemokines regulating the recruitment of different immune cells into transplanted allograft and on in vitro regulation of the same chemokines release by interactions of renal proximal epithelial cells with monocyte/macrophage cell line stimulated with TNF alpha. In a group of 44 patients with acute rejection, higher serum pretransplant levels of CXCL1, CXCL5, CXCL6, CCL2, CCL21, and particularly CXCL10 and CX3CL1(both p < 0.001) were found suggesting their higher proinflammatory status as compared to subjects with the uncomplicated outcome. In samples collected at the day of biopsy positive for acute rejection, chemokines CXCL9 and CXCL11 attracting preferentially Th1 lymphocytes were found to be upregulated. In our in vitro model with TNF alpha induction, renal proximal epithelial cells seemed to be a more potent source of chemokines attracting neutrophils as compared to monocyte/macrophage cell line but the coculture of these cells potentiated release of neutrophilic chemokines CXCL5 and CXCL6. Similar augmentation of chemokine production was found also in the case of CCL2. On the other hand, adding of monocytes/macrophages to a culture of renal epithelial cells suppressed the release of CXCL10 and CXCL11 attracting T lymphocytes. We assume from our data that in kidney allograft transplantation, chemokines attracting neutrophils, T lymphocytes, and monocytes are induced simultaneously and measurement some of them in combination might be used as biomarkers of acute rejection. Mutual cell-cell interactions of immune cells with renal parenchyma seem to be important for fine regulation of chemokine release.

Formalin-fixed paraffin-embedded renal biopsy tissues: an underexploited biospecimen resource for gene expression profiling in IgA nephropathy

Primary IgA nephropathy (IgAN) diagnosis is based on IgA-dominant glomerular deposits and histological scoring is done on formalin-fixed paraffin embedded tissue (FFPE) sections using the Oxford classification. Our aim was to use this underexploited resource to extract RNA and identify genes that characterize active (endocapillary–extracapillary proliferations) and chronic (tubulo-interstitial) renal lesions in total renal cortex. RNA was extracted from archival FFPE renal biopsies of 52 IgAN patients, 22 non-IgAN and normal renal tissue of 7 kidney living donors (KLD) as controls. Genome-wide gene expression profiles were obtained and biomarker identification was carried out comparing gene expression signatures a subset of IgAN patients with active (N = 8), and chronic (N = 12) renal lesions versus non-IgAN and KLD. Bioinformatic analysis identified transcripts for active (DEFA4,TNFAIP6,FAR2) and chronic (LTB,CXCL6, ITGAX) renal lesions that were validated by RT-PCR and IHC. Finally, two of them (TNFAIP6 for active and CXCL6 for chronic) were confirmed in the urine of an independent cohort of IgAN patients compared with non-IgAN patients and controls. We have integrated transcriptomics with histomorphological scores, identified specific gene expression changes using the invaluable repository of archival renal biopsies and discovered two urinary biomarkers that may be used for specific clinical decision making.

Fn14 Deficiency Ameliorates Anti-dsDNA IgG-Induced Glomerular Damage in SCID Mice

Many studies have demonstrated that anti-dsDNA IgG is closely associated with lupus nephritis. Recently, it was found that activation of the fibroblast growth factor-inducible 14 (Fn14) signaling pathway damages glomerular filtration barrier in MRL/lpr lupus-prone mice. However, MRL/lpr mice have high titers of serum autoantibodies other than anti-dsDNA IgG. The aim of this study was to further explore the effect of Fn14 deficiency on anti-dsDNA IgG-induced glomerular damage in severe combined immunodeficiency (SCID) mice that have no endogenous IgG. Fn14 deficiency was generated in SCID mice. The murine hybridoma cells producing control IgG or anti-dsDNA IgG were intraperitoneally injected into mice. In two weeks, the urine, serum, and kidney tissue samples were harvested from mice at sacrifice. It showed that the injection of anti-dsDNA IgG, but not control IgG hybridoma cells, induced proteinuria and glomerular damage in SCID mice. Between the wild-type (WT) and knockout (KO) mice injected with anti-dsDNA IgG hybridoma cells, the latter showed a decrease in both proteinuria and glomerular IgG deposition. The histopathological changes, inflammatory cell infiltration, and proinflammatory cytokine production were also attenuated in the kidneys of the Fn14-KO mice upon anti-dsDNA IgG injection. Therefore, Fn14 deficiency effectively protects SCID mice from anti-dsDNA IgG-induced glomerular damage.

Urinary cytokines and mRNA expression as biomarkers of disease activity in lupus nephritis

Introduction

Renal involvement is one of the most serious manifestations of systemic lupus erythematosus, but non-invasive assessment of inflammatory response in kidneys is challenging. In this study we aimed to validate markers of active lupus nephritis (LN) using urine immune profiling.

Methods

Urine and serum cytokines (17-plex array) and urine mRNA expression (∼40 immune and glomerular injury genes) were measured in LN patients with active disease ( n = 17) during remission ( n = 16) and in healthy subjects ( n = 18).

Results

Urine and serum levels of CCL2, CCL5 and CXCL10 were elevated in active LN as compared with disease remission (best discrimination for urine CXCL10 and CCL2) and correlated with LN activity. In the active disease, urinary cell transcriptome showed marked upregulation of proinflammatory cytokines (e.g. TNF, CCL2, CCL5, CXCL10), and type-1 immunity-related genes (e.g. CD3G, CD4, TBX21, IFNG). An active pattern of gene expression was also observed in four patients in remission, who had moderately increased urinary leucocyte count. Two patients from this group developed renal exacerbation during the following 3 months. Markers of type-17 immune axis (e.g. IL-17A) were not significantly increased in active LN.

Conclusions

Active LN patients were characterized by marked increase of proinflammatory mediators in the urine. Urine cytokines (CCL2 and CXCL10) and type-1 T-cell-related gene markers in the urine sediment had similar diagnostic performance in detection of active LN.

The role of TLR2 in the acute inflammatory response induced by Bothrops atrox snake venom

Envenomation by snakes of the species Bothrops atrox induces local and systemic effects. Local effects include drastic tissue damage and a marked inflammatory response as a result of the synthesis and release of a variety of protein and lipid mediators. Toll-like receptor (TLR) signaling pathways can play an important role in this response, leading to synthesis of these inflammatory mediators. This study investigated the influence of TLR2 on the acute inflammatory response induced by Bothrops atrox venom. Wild-type C57BL/6 mice (WT) and TLR2 gene knockout mice (TLR2(-/-)) were injected with Bothrops atrox venom (BaV), and the following responses to the venom were assessed in peritoneal exudate: leukocyte accumulation; release of mediators, including CCL-2, IL-10, IL-1β, IL-6 and LTB4; protein expression of COX-1 and COX-2; and quantification of their products PGE2 and TXA2. After injection with BaV, the TLR2(-/-) mice (TLR2(-/-)BaV) had higher levels of IL-6 and CCL-2 than WT animals kept under the same conditions (WTBaV), together with an accumulation of polymorphonuclear leukocytes (PMNs), inhibition of IL-1β and LTB4 and reduced mononuclear leukocyte influx. However, no significant differences in COX-2 protein expression or PGE2, TXA2 and IL-10 production between the TLR2(-/-)BaV and WTBav animals were observed. Together, these results indicate that the signaling pathway activated by TLR2 acts by modulating the induced inflammatory response to BaV through the direct action of venom-associated molecular patterns (VAMPs) or indirectly by forming damage-associated molecular patterns (DAMPs) and that this may have important therapeutic implications.

Ameliorative Effects of Curcumin on Fibrinogen-Like Protein-2 Gene Expression, Some Oxido-Inflammatory and Apoptotic Markers in a Rat Model of l-Arginine-Induced Acute Pancreatitis

The aim of the study was to investigate the ameliorative effects of curcumin on fibrinogen like protein-2 (fgl-2), some oxido-inflammatory and apoptotic markers in rat-induced acute pancreatitis (AP). Seventy-five albino rats were divided into control group, l-arginine (l-Arg)-induced AP group, curcumin pre-treated group before AP induction, curcumin post-treated group after AP induction, and curcumin injected group only. AP group showed severe necrotizing pancreatitis confirmed by histopathological changes and elevations in serum amylase and lipase activities, levels of epithelial neutrophil-activating peptide 78, tissue content of protein carbonyls, levels of tumor necrosis factor α, and caspase-3 as well as myeloperoxidase activity. Significant elevation in pancreatic fgl-2 mRNA expression was detected in AP group. Improvement of all parameters was detected with increase of caspase-3 in both curcumin-treated groups that confirmed curcumin ameliorative effects against AP through induction of apoptosis and inhibition of micro-thrombosis, inflammation, and oxidative stress.

Gene silencing of MCP-1 prevents microglial activation and inflammatory injury after intracerebral hemorrhage

Microglia are activated after intracerebral hemorrhage and induce neuron death by releasing proinflammatory cytokines and chemokines. However, the related mechanism of microglia activation in such conditions remains elusive. MCP-1, the ligand of CCR2 expressed in the central nervous system, could promote microglia proliferation, survival and cytokine secretion. According to the previous findings, we make a hypothesis that whether alternation of MCP-1 level could attenuate microglia activation and toxicity to neuron in intracerebral hemorrhage. To identify that, we interfere with the MCP-1 expression of microglia by RNAi technology, and coculture the microglia and neuron in ICH. The results demonstrated that MCP-1 RNAi inhibited TNF-α, IL-1β and IL-6 expression in microglia and attenuated neuron injury. In conclusion, the present study suggests that MCP-1 might promote ICH induced microglia activation and toxicity to neuron, and MCP-1 RNAi might provide promising therapeutical strategy for ICH.

Overexpression of Growth-Related Oncogene-β Is Associated with Tumorigenesis, Metastasis, and Poor Prognosis in Ovarian Cancer

Background. Growth-related oncogene- (GRO-) β is a member of the CXC chemokine family, which may mediate various functions, such as attracting neutrophils to sites of inflammation, regulating angiogenesis, and participating in tumorigenesis and progression. However, the expression of GRO-β in ovarian cancer and its relationship to the clinical characteristics of this disease remain poorly understood. Methods. In this study, immunohistochemical analysis using tissue microarray (TMA) was employed to evaluate the expression of GRO-β in ovarian cancer and to contrast expression with normal ovarian epithelial cells and oviduct epithelial cells. Next, we observed the correlation between GRO-β expression and clinicopathological features of ovarian cancer as well as patient outcome. Results. High GRO-β cytoplasmic expression was observed in 55.15% of patients with ovarian cancer, which was related to lymph node or other metastases (P < 0.001), ascites (P = 0.027), and International Federation of Obstetricians and Gynaecologists (FIGO) stage (P = 0.032). Kaplan-Meier survival and Cox regression analysis revealed that high GRO-β expression (P = 0.002) and high CA19-9 level (P = 0.003) were independent prognostic indicators of poor outcome in ovarian cancer. Conclusions. Overall, high GRO-β expression correlates with poor prognosis and contributes to ovarian cancer tumorigenesis and metastasis.

Clinical significance of serum expression of GROβ in hepatocellular carcinoma

This study aimed to determine whether serum levels of growth-related gene product β (GROβ) were associated with clinical parameters in hepatocellular carcinoma (HCC). Using an enzyme-linked immunosorbent assay (ELISA), the serum GROβ levels of 80 HCC patients, 65 patients with benign diseases of the liver, and 60 healthy volunteers were examined. The association between serum levels of GROβ and clinical parameters of HCC was analyzed statistically. The serum GROβ levels were much lower in benign diseases and healthy volunteers than HCC, and associated with tumor node metastasis (TNM) stages, tumor size, vascular thrombosis, capsule, and Edmondson grading of HCC (p < 0.05), but not with gender, age, liver cirrhosis, or the level of AFP (p > 0.05). We have demonstrated that GROβ, as an oncogene product, contributed to tumorigenesis and metastasis of HCC.

Role of Serum Levels of Angiogenic Cytokines in Assessment of Angiogenesis after Stem Cell Therapy of Diabetic Patients with Critical Limb Ischemia

The release of proangiogenic cytokines into the circulation after stem cell (SC) therapy and compensatory increase of angiogenesis inhibitors may reflect local vasculogenesis but also can increase the risk of side effects. The aim of our study was to evaluate serum levels of angiogenic cytokines with regard to the assessment of local and systemic vasculogenesis in diabetic patients with no-option critical limb ischemia (NO-CLI). Twenty-five diabetic patients with NO-CLI treated with SCs isolated from bone marrow or stimulated peripheral blood were included in the study. Serum levels of proangiogenic cytokines (VEGF, bFGF, Ang-1, PDGF-AA, and PDGF-BB) and an antiangiogenic cytokine (endostatin) were assessed 6 months after cell treatment, compared to baseline values, and correlated with the number of injected CD34+ cells. The clinical effect of SC therapy (assessed by changes in TcPO2) and potential systemic vasculogenesis (assessed by eye fundus examination) were evaluated after 6 months. Serum levels of angiogenic inhibitor endostatin increased significantly after 1 and 3 months ( p = 0.0003), but no significant increase in serum levels of proangiogenic cytokines was observed. A significant correlation between number of injected CD34+ cells and serum levels of endostatin was observed ( r = 0.41, p < 0.05); however, proangiogenic cytokines did not correlate with CD34+ cells. No correlation between increase in TcPO2 after treatment and serum levels of any of the angiogenic cytokines were seen, and no signs of systemic vasculogenesis in the retina were observed after 6 months. Despite the significant increase in the levels of the angiogenic inhibitor endostatin following SC treatment, there was no risk of systemic vasculogenesis after SC therapy as documented by serum levels of proangiogenic cytokines or changes in the retina.

Cytokine networking of innate immunity cells: a potential target of therapy

Innate immune cells, particularly macrophages and epithelial cells, play a key role in multiple layers of immune responses. Alarmins and pro-inflammatory cytokines from the IL (interleukin)-1 and TNF (tumour necrosis factor) families initiate the cascade of events by inducing chemokine release from bystander cells and by the up-regulation of adhesion molecules required for transendothelial trafficking of immune cells. Furthermore, innate cytokines produced by dendritic cells, macrophages, epithelial cells and innate lymphoid cells seem to play a critical role in polarization of helper T-cell cytokine profiles into specific subsets of Th1/Th2/Th17 effector cells or regulatory T-cells. Lastly, the innate immune system down-regulates effector mechanisms and restores homoeostasis in injured tissue via cytokines from the IL-10 and TGF (transforming growth factor) families mainly released from macrophages, preferentially the M2 subset, which have a capacity to induce regulatory T-cells, inhibit the production of pro-inflammatory cytokines and induce healing of the tissue by regulating extracellular matrix protein deposition and angiogenesis. Cytokines produced by innate immune cells represent an attractive target for therapeutic intervention, and multiple molecules are currently being tested clinically in patients with inflammatory bowel disease, rheumatoid arthritis, systemic diseases, autoinflammatory syndromes, fibrosing processes or malignancies. In addition to the already widely used blockers of TNFα and the tested inhibitors of IL-1 and IL-6, multiple therapeutic molecules are currently in clinical trials targeting TNF-related molecules [APRIL (a proliferation-inducing ligand) and BAFF (B-cell-activating factor belonging to the TNF family)], chemokine receptors, IL-17, TGFβ and other cytokines.

Tumor necrosis factor receptor 2: its contribution to acute cellular rejection and clear cell renal carcinoma

Tumor necrosis factor receptor 2 (TNFR2) is a type I transmembrane glycoprotein and one of the two receptors that orchestrate the complex biological functions of tumor necrosis factor (TNF, also designed TNF-α). Accumulating experimental evidence suggests that TNFR2 plays an important role in renal disorders associated with acute cellular rejection and clear cell renal carcinoma but its exact role in these settings is still not completely understood. This papers reviews the factors that may mediate TNFR2 induction in acute cellular rejection and clear cell renal carcinoma and its contribution to these conditions and discusses its therapeutic implications. A greater understanding of the function of TNFR2 may lead to the development of new anti-TNF drugs.

Acute plasma biomarkers of T cell activation set-point levels and of disease progression in HIV-1 infection

T cell activation levels, viral load and CD4(+) T cell counts at early stages of HIV-1 infection are predictive of the rate of progression towards AIDS. We evaluated whether the inflammatory profile during primary HIV-1 infection is predictive of the virological and immunological set-points and of disease progression. We quantified 28 plasma proteins during acute and post-acute HIV-1 infection in individuals with known disease progression profiles. Forty-six untreated patients, enrolled during primary HIV-1 infection, were categorized into rapid progressors, progressors and slow progressors according to their spontaneous progression profile over 42 months of follow-up. Already during primary infection, rapid progressors showed a higher number of increased plasma proteins than progressors or slow progressors. The plasma levels of TGF-β1 and IL-18 in primary HIV-1 infection were both positively associated with T cell activation level at set-point (6 months after acute infection) and together able to predict 74% of the T cell activation variation at set-point. Plasma IP-10 was positively and negatively associated with, respectively, T cell activation and CD4(+) T cell counts at set-point and capable to predict 30% of the CD4(+) T cell count variation at set-point. Moreover, plasma IP-10 levels during primary infection were predictive of rapid progression. In primary infection, IP-10 was an even better predictor of rapid disease progression than viremia or CD4(+) T cell levels at this time point. The superior predictive capacity of IP-10 was confirmed in an independent group of 88 HIV-1 infected individuals. Altogether, this study shows that the inflammatory profile in primary HIV-1 infection is associated with T cell activation levels and CD4(+) T cell counts at set-point. Plasma IP-10 levels were of strong predictive value for rapid disease progression. The data suggest IP-10 being an earlier marker of disease progression than CD4(+) T cell counts or viremia levels.

Urinary chemokines and anti-inflammatory molecules in renal transplanted patients as potential biomarkers of graft function: a prospective study

PURPOSE

Clinical- and histopathology-based scores are the limited predictors of allograft outcome. Thus, predictors of allograft survival still remain a challenge. This study aimed to evaluate the urinary levels of chemokines and anti-inflammatory molecules at 30, 90, and 300 days after renal transplantation and to further correlate these measurements to graft function.

METHODS

Glomerular filtration rate (GFR) and urinary levels of MCP-1/CCL2, MIP-1α/CCL3, RANTES/CCL5, IL-8/CXCL8, IP-10/CXCL10, interleukin-1 receptor antagonist, soluble tumor necrosis factor receptor-1, and receptor-2 were determined at 30, 90, and 300 days after renal transplantation in 22 patients. Transplanted patients were also divided according to the type of donor (living donor, LD, n = 13 or deceased donor, DD, n = 9).

RESULTS

Urinary levels of all molecules, except MIP-1α/CCL3, remained unchanged at 30, 90, and 300 days after transplantation in our 22 patients. MIP-1α/CCL3 levels significantly reduced from 30 to 300 days and showed a negative correlation with GFR at 30 days. The comparison between LD and DD groups showed similar levels of all markers, except for MCP-1/CCL2, which presented higher values in LD than in DD at 30 days. sTNFR1 and MCP-1/CCL2 significantly reduced from 30 to 300 days in LD group, but only sTNFR2 concentrations at 30 days were negatively correlated with GFR at 300 days. On the other hand, in DD group, IL-1Ra concentrations at 30 and at 90 days were positively correlated with GFR at 300 days.

CONCLUSION

Urinary chemokine and anti-inflammatory molecules measurements may be a promising tool in the follow-up of renal transplanted patients.

Bench-to-bedside review: Ventilation-induced renal injury through systemic mediator release--just theory or a causal relationship?

We review the current literature on the molecular mechanisms involved in the pathogenesis of acute kidney injury induced by plasma mediators released by mechanical ventilation. A comprehensive literature search in the PubMed database was performed and articles were identified that showed increased plasma levels of mediators where the increase was solely attributable to mechanical ventilation. A subsequent search revealed articles delineating the potential effects of each mediator on the kidney or kidney cells. Limited research has focused specifically on the relationship between mechanical ventilation and acute kidney injury. Only a limited number of plasma mediators has been implicated in mechanical ventilation-associated acute kidney injury. The number of mediators released during mechanical ventilation is far greater and includes pro- and anti-inflammatory mediators, but also mediators involved in coagulation, fibrinolysis, cell adhesion, apoptosis and cell growth. The potential effects of these mediators is pleiotropic and include effects on inflammation, cell recruitment, adhesion and infiltration, apoptosis and necrosis, vasoactivity, cell proliferation, coagulation and fibrinolysis, transporter regulation, lipid metabolism and cell signaling. Most research has focused on inflammatory and chemotactic mediators. There is a great disparity of knowledge of potential effects on the kidney between different mediators. From a theoretical point of view, the systemic release of several mediators induced by mechanical ventilation may play an important role in the pathophysiology of acute kidney injury. However, evidence supporting a causal relationship is lacking for the studied mediators.

Clinical significance of serum expression of GROβ in esophageal squamous cell carcinoma

AIM: To determine the association between serum levels of growth-related gene product β (GROβ) and clinical parameters in esophageal squamous cell carcinoma (ESCC).

METHODS: Using enzyme-linked immunosorbent assay, serum GROβ levels were measured in ESCC patients (n = 72) and healthy volunteers (n = 83). The association between serum levels of GROβ and clinical parameters of ESCC was analyzed statistically.

RESULTS: The serum GROβ levels were much higher in ESCC patients than in healthy controls (median: 645 ng/L vs 269 ng/L, P < 0.05). Serum GROβ levels were correlated positively with tumor size, lymph node metastasis, and tumor-node-metastasis (TNM) staging, but not with gender or the histological grade of tumors in ESCC patients. The sensitivity and specificity of the assay for serum GROβ were 73.61% and 56.63%, respectively.

CONCLUSION: GROβ may function as an oncogene product and contribute to tumorigenesis and metastasis of ESCC.

RNA interference-directed caveolin-1 knockdown sensitizes SN12CPM6 cells to doxorubicin-induced apoptosis and reduces lung metastasis

Human renal cell carcinoma (HRCC) is characterized by a high level of resistance to all treatment modalities. Therefore, the investigation of global gene expression in HRCC might help understand its biologic behavior and develop treatment strategies. Using cDNA microarray analysis, we initially compared gene expression profiles between HRCCs and adjacent normal tissues, and found that 87 were up-regulated and 127 genes were down-regulated. Next, a subset of genes, twofold differentially expressed, were validated by Northern blotting. Unexpectedly, caveolin-1, a gene reported to be a tumor suppressor gene, was found to be up-regulated in HRCC tissues. Expression level of caveolin-1 in SN12CPM6 (high metastatic clone) was higher than in SN12C (low metastatic clone), and SN12CPM6 was more resistant to doxorubicin (DXR) than SN12C. Caveolin-1 gene was slightly induced in surviving SN12C cells after DXR treatment. Furthermore, SN12CPM6-siCav1 cells, which were transfected with siRNA of cavelon-1 gene, were more sensitive to DXR, compared to SN12CPM6, but reduction of caveolin-1 gene expression did not affect tumor formation in subcapsule of kidney and lung metastasis. On the other hand, induction of caveolin-1 gene affected the production of lung metastasis under anti-cancer drug treatment: the incidence of pulmonary metastasis was significantly lower in SCID mice injected with SN12CPM6-siCav1 cells, and the number of pulmonary nodules decreased significantly (p = 0.0004). The above results together suggest that caveolin-1 may confer a growth advantage to cancer cells during DXR chemotherapy and surviving HRCC cells eventually might develop lung metastasis.

Etanercept treatment reduces the serum levels of interleukin-15 and interferon-gamma inducible protein-10 in patients with rheumatoid arthritis

Tumor necrosis factor-alpha (TNF-alpha) has an essential role in the pathogenesis of rheumatoid arthritis (RA) and has been known to induce the production of several inflammatory molecules in vivo. To analyze in vivo the active mechanism of the TNF-alpha blocking agent, etanercept, the serum levels of the cytokine interleukin-15 (IL-15) and the chemokines growth-regulated protein-alpha (Gro-alpha), and interferon-gamma inducible protein-10 (IP-10) in RA patients were measured. Twenty-two patients with RA were administered etanercept once or twice a week for more than 6 months. The clinical and laboratory parameters were measured and serum levels of IL-15, Gro-alpha, and IP-10 were determined using enzyme-linked immunosorbent assay (ELISA) kits at the baseline and at 3 and 6 months after the initial treatment. Additionally, the production of IL-15 and IP-10 by cultured synovial cells stimulated with TNF-alpha from RA patients was determined by ELISA. A significant decrease in serum levels of IL-15 and IP-10 was observed at 3 and 6 months after initial treatment with etanercept, but not in those of Gro-alpha. TNF-alpha induced production of IP-10, but not IL-15 in cultured synovial cells from RA patients. This study demonstrated for the first time the reduction of IP-10 and IL-15 production in RA patients as active mechanisms of etanercept.