Effects of combinations of anti-rheumatic drugs on the production of vascular endothelial growth factor and basic fibroblast growth factor in cultured synoviocytes and patients with rheumatoid arthritis

Systematic Review: Targeted Molecular Imaging of Angiogenesis and Its Mediators in Rheumatoid Arthritis

Extensive angiogenesis is a characteristic feature in the synovial tissue of rheumatoid arthritis (RA) from a very early stage of the disease onward and constitutes a crucial event for the development of the proliferative synovium. This process is markedly intensified in patients with prolonged disease duration, high disease activity, disease severity, and significant inflammatory cell infiltration. Angiogenesis is therefore an interesting target for the development of new therapeutic approaches as well as disease monitoring strategies in RA. To this end, nuclear imaging modalities represent valuable non-invasive tools that can selectively target molecular markers of angiogenesis and accurately and quantitatively track molecular changes in multiple joints simultaneously. This systematic review summarizes the imaging markers used for single photon emission computed tomography (SPECT) and/or positron emission tomography (PET) approaches, targeting pathways and mediators involved in synovial neo-angiogenesis in RA.

RS3PE Following Treatment With Combination of Hormonal Therapies Plus Ipilimumab in a Patient With Metastatic Prostate Cancer

Introduction

Immune checkpoint inhibitors (ICIs) are often associated with inflammatory toxicities known as immune-related adverse events (irAEs). Remitting seronegative symmetrical synovitis with pitting edema (RS3PE) is an atypical inflammatory arthritis. Herein, we report a case of RS3PE in a patient with metastatic prostate cancer who was receiving a combination of second-generation hormonal therapies plus ipilimumab.

Case Presentation

A 59-year-old man with metastatic prostate cancer developed sudden onset of pain and swelling of the right hand after 15 weeks of treatment with second-generation hormonal therapies plus three cycles of ipilimumab. Symptoms alternated to the left hand. Physical examination showed tender, pitting edema of the left hand with tenderness on the right second through fifth metacarpal phalangeal joints, leading to the diagnosis of RS3PE. Ipilimumab was withheld, and the RS3PE self-resolved; however, 1 month later, the patient had another flare of RS3PE. A bone scan showed active inflammation on bilateral wrists and hands. Methotrexate was initiated, and his symptoms resolved over a few days. Methotrexate was discontinued 2 months later, and RS3PE has been in complete remission. His prostate cancer progressed, and radium-223 treatment was initiated.

Conclusion

To the best of our knowledge, this is the first reported case of RS3PE after the combined second-generation hormonal therapy plus ipilimumab. Both rheumatologists and oncologists should be aware that RS3PE can develop as an irAE. Understanding the mechanism of ICI therapy-associated RS3PE is critical to identify predictive biomarkers and develop optimal therapeutic strategies that do not sacrifice antitumor immunity.

Sorafenib Reveals Anti-Arthritic Potentials in Collagen Induced Experimental Arthritis Model

Objectives

This study aims to examine the effects of sorafenib on a collagen-induced arthritis model.

Materials and methods

The study included 50 randomly selected female Wistar-albino rats (8-10-week-old, weighing between 200 g to 250 g). The rats were divided into five equal groups as control, arthritis, etanercept, sorafenib high-dose, and sorafenib low-dose groups, respectively. Arthritis was induced by injecting mixed intradermal chicken type II collagen and incomplete Freund's adjuvant. Twenty-four hours after the advent of arthritis; rats in group 3 were injected subcutaneous etanercept (6 mg/kg/week), while those in groups 4 and 5 were given sorafenib (10 or 30 mg/ kg/day) orally until they were sacrificed on the 34th day. The rat claws and trunk bloods were carefully examined to note perisynovial inflammation and cartilage/bone injury through histopathology. Tissue vascular endothelial growth factor (VEGF) and VEGF receptor levels were carefully checked using western blot analysis.

Results

Analysis of the experimental data showed that collagen-induced arthritis decreased in treatments groups after 12-13 days and 34th day in contrast with the arthritis group. Histopathological examination revealed broad perisynovial inflammation and cartilage/bone break down in the arthritis group. Compared to the control group, tissue VEGF and VEGF receptor levels increased in the arthritis group. Sorafenib and etanercept decreased tissue VEGF and VEGF receptor levels, perisynovial inflammation, damage of cartilage/bone.

Conclusion

Our findings indicate that sorafenib treatment ameliorates collagen-induced arthritis with anti-VEGF effectiveness.

Tripterygium wilfordii Inhibiting Angiogenesis for Rheumatoid Arthritis Treatment

Rheumatoid arthritis (RA) is a chronic inflammatory disease with a serious pre-vascular inflammatory phase, followed by significant increase in vessel growth. Inhibition of angiogenesis is a novel therapeutic strategy against RA. The Chinese herbal remedy Tripterygium wilfordii, Hook. f. (TwHf) has been reported to be therapeutically efficacious in the treatment of RA. Recent studies have revealed that treatment with TwHf extracts inhibit angiogenesis of RA, thereby elaborately attenuation RA symptom. This review mainly addresses the anti-angiogenesis effect of TwHf in treatment of RA.

[Angiogenesis and its association with inflammation and fibrosis in course of the development of scleroderma systematica]

Scleroderma systematica (SDS) is a chronic autoimmune disease characterized by severe fibrosis of the skin and visceral organs. Vascular disorders are an important component of the disease, but the mechanisms of vascular injury and their prevention are unknown. Angiogenesis in SDS is accompanied by the apparent expression of angiogenic factors, such as vascular endothelial growth factor and basal or fibroblast growth factor. Imbalance of these markers with endostatin expression is noted. This disease is characterized by inflammation and the intensity of neoangiogenesis correlates with its activity. The fact that there may be a pathogenic relationship between the processes of angiogenesis and the intensity of further fibrosis is shown. There is a vicious circle of the induction and maintenance of the processes of angiogenesis, inflammation, and fibrosis in SDS.

Addition of another disease-modifying anti-rheumatic drug to methotrexate reduces the flare rate within 2 years after infliximab discontinuation in patients with rheumatoid arthritis: an open, randomized, controlled trial

OBJECTIVES

We examined whether the addition of another conventional disease-modifying anti-rheumatic drugs (DMARDs) to methotrexate (MTX) upon infliximab (IFX) discontinuation in well-controlled rheumatoid arthritis (RA) patients could suppress subsequent disease flare.

METHODS

RA patients maintaining DAS28-CRP (Disease Activity Score of 28 joints with C-reactive protein) scores < 2.6 for ≥ 6 months with IFX were randomized either to receive addition of bucillamine (BUC) to MTX (BUC + MTX group; n = 24) or not (MTX group; n = 31) upon discontinuing IFX. The primary endpoint was the flare rate within 2 years of IFX discontinuation.

RESULTS

Six patients discontinuing MTX during the study were excluded from analyses. Seventeen patients (63.0%) experienced flares in the MTX group, which was significantly reduced in the BUC + MTX group (31.8%; p = 0.045). Further, the flare rates differed significantly between remission and non-remission by a Boolean definition upon IFX discontinuation in the MTX group (40.0% vs. 91.7%, respectively; p = 0.014), but they were comparable in the BUC + MTX group. BUC treatment was interrupted in seven patients due to rash, proteinuria and incompliance.

CONCLUSIONS

DMARDs combination therapy may be a better treatment strategy than MTX monotherapy for maintaining RA control after successful discontinuation of biological agents.

Anti-angiogenic effect of triptolide in rheumatoid arthritis by targeting angiogenic cascade

Rheumatoid arthritis (RA) is characterized by a pre-vascular seriously inflammatory phase, followed by a vascular phase with high increase in vessel growth. Since angiogenesis has been considered as an essential event in perpetuating inflammatory and immune responses, as well as supporting pannus growth and development of RA, inhibition of angiogenesis has been proposed as a novel therapeutic strategy for RA. Triptolide, a diterpenoid triepoxide from Tripterygium wilfordii Hook F, has been extensively used in treatment of RA patients. It also acts as a small molecule inhibitor of tumor angiogenesis in several cancer types. However, it is unclear whether triptolide possesses an anti-angiogenic effect in RA. To address this problem, we constructed collagen-induced arthritis (CIA) model using DA rats by the injection of bovine type II collagen. Then, CIA rats were treated with triptolide (11-45 µg/kg/day) starting on the day 1 after first immunization. The arthritis scores (P<0.05) and the arthritis incidence (P<0.05) of inflamed joints were both significantly decreased in triptolide-treated CIA rats compared to vehicle CIA rats. More interestingly, doses of 11~45 µg/kg triptolide could markedly reduce the capillaries, small, medium and large vessel density in synovial membrane tissues of inflamed joints (all P<0.05). Moreover, triptolide inhibited matrigel-induced cell adhesion of HFLS-RA and HUVEC. It also disrupted tube formation of HUVEC on matrigel and suppressed the VEGF-induced chemotactic migration of HFLS-RA and HUVEC, respectively. Furthermore, triptolide significantly reduced the expression of angiogenic activators including TNF-α, IL-17, VEGF, VEGFR, Ang-1, Ang-2 and Tie2, as well as suppressed the IL1-β-induced phosphorylated of ERK, p38 and JNK at protein levels. In conclusion, our data suggest for the first time that triptolide may possess anti-angiogenic effect in RA both in vivo and in vitro assay systems by downregulating the angiogenic activators and inhibiting the activation of mitogen-activated protein kinase downstream signal pathway.

Wen Luo Yin inhibits angiogenesis in collagen-induced arthritis rat model and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE AND AIM OF THE STUDY

Wen Luo Yin (WLY) is a traditional Chinese formula, which has the traditional use of scattering cold pathogen, draining dampness, freeing the flow of network vessels and relieving pains. It is extensively used in the treatment of rheumatoid arthritis (RA) patients for more than 2000 years, but its actions on angiogenesis of RA have not been clarified. The present study aims to determine the anti-angiogenic activity of WLY on collagen-induced arthritis (CIA) rat model and in human fibroblast-like synoviocytes of RA (HFLS-RA) and human umbilical vein endothelial cells (HUVEC).

MATERIALS AND METHODS

For in vivo experiment, arthritis was induced by immunization with bovine II collagen in DA rats. Treatment with WLY (3.45, 6.9, 13.8 g/kg, p.o., daily), or vehicle began from day 1 to day 28 of first immunization. The arthritis score, arthritis incidence, microfocal computed tomography analysis and histopathology evaluation of inflamed joints were assessed. Angiogenesis was measured by synovial vessel density with immunohistochemistry and histomorphometric analysis in synovial membrane tissues of joints. For in vitro experiments, HFLS-RA and HUVEC were used. Assays to determine HFLS-RA migration and adhesion were performed in the presence of vascular endothelial growth factor (VEGF)165 or interleukin (IL)-1β and/or the WLY (8, 16, 32 mg/ml). Angiogenesis was assessed by measuring the migration, adhesion, and tube formation of HUVEC. Further the effect of treatment with WLY on expression levels of angiogenic activators in sera of CIA rats and in IL-1β-induced HFLS-RA were evaluated by enzyme linked immunosorbent assay.

RESULTS

WLY significantly decreased the arthritis score and arthritis incidence, and inhibited inflammation, pannus formation, cartilage and bone destruction of inflamed joints in CIA rats. More interestingly, doses of 3.45-13.8 g/kg WLY could markedly reduce the capillaries, small, medium and large vessel density in synovial membrane tissues of inflamed joints. Moreover, WLY suppressed the VEGF-induced chemotactic migration of HFLS-RA and HUVEC, and inhibited matrigel-induced cell adhesion of them. It also disrupted tube formation of HUVEC on matrigel. Furthermore, WLY significantly reduced the expression of angiogenic activators including tumor necrosis factor-α, IL-1β, IL-17, VEGF, VEGFR, angiopoietin (Ang)-1, Ang-2 and Ang-2 receptor in sera of CIA rats and/or in IL-1β-induced HFLS-RA/HUVEC.

CONCLUSIONS

Our data suggest for the first time that WLY posses the anti-angiogenic effect in RA both in vivo and in vitro by downregulating angiogenic activators.

Emerging avenues linking inflammation, angiogenesis and Sjögren's syndrome

Sjögren's syndrome (SS) is an autoimmune disease characterized by an inflammatory mononuclear infiltration and the destruction of epithelial cells of the lachrymal and salivary glands. The aetiology is unknown. The expression "autoimmune epithelitis" has been proposed as an alternative to SS, in view of the emerging central role of the epithelial cells in the disease pathogenesis. At the biomolecular level, the epithelial cells play an important role in triggering the autoimmune condition via antigen presentation, apoptosis, and chemokine and cytokines release. Inflammation and angiogenesis are frequently coupled in the pathological conditions associated to autoimmune diseases, and an angiogenic imbalance contributes to the pathogenesis of a number of inflammatory disorders. This work reviews the current knowledge of the molecular and cellular mechanisms underlying the pathogenesis of the inflammatory reactions that characterize SS. The literature and our data on the role of angiogenesis in the pathophysiology of the disease are discussed.

Relationship of ultrasonographic findings with synovial angiogenesis modulators in different forms of knee arthritides

Angiogenesis is controlled by a variety of angiogenesis stimulators and inhibitors. The increased power Doppler (PD) signals determined by ultrasonography is an indirect marker of synovial vascularity in arthritis. We aimed to investigate relationship between ultrasonographic findings and synovial angiogenesis modulators. Thirteen Behcet's disease (BD), 15 spondyloarthropathy, 21 rheumatoid arthritis (RA), and 15 osteoarthritis (OA) patients with knee arthritis were included. Cumulative effusion, synovial hypertrophy, and PD signal scores were calculated in arthritic joints. In synovial fluid samples, angiogenesis inhibitors (angiostatin, thrombospondin-1, and endostatin) and stimulators [bFGF (basic fibroblast growth factor), angiopoietin-1] were studied. The comparisons between groups were made by Kruskal-Wallis test, and correlation analysis was calculated with Pearson and Spearman tests. Effusion scores were significantly higher in inflammatory arthritis than in OA. Synovial hypertrophy scores were higher in RA and spondylarthritis than in OA and BD. PD scores were not different between the groups. Synovial angiostatin and bFGF levels were significantly higher in patients with inflammatory arthritis than in OA. Cumulative effusion scores were positively correlated with angiopoietin-1, angiostatin, and bFGF and negatively correlated with thrombospondin-1 levels. Synovial hypertrophy scores were positively correlated with angiostatin and bFGF levels and negatively correlated with thrombospondin-1. No correlation was found between PD scores and modulators of angiogenesis. In large joints like knee, detecting PD signals alone was not sufficient to assess the angiogenesis. However, cumulative activity scores were positively correlated with angiogenesis stimulators. Therefore, when investigating the angiogenesis, PD technique should be added to gray-scale examinations.

Sjögren's syndrome pathological neovascularization is regulated by VEGF-A-stimulated TACE-dependent crosstalk between VEGFR2 and NF-κB

We explore the involvement of tumor necrosis factor α (TNF-α)-converting enzyme (TACE) in vascular endothelial growth factor (VEGF) and its receptor 2 (VEGFR2) (VEGF-A/VEGFR2)-mediated angiogenesis in Sjögren's syndrome (SS), one of the most common autoimmune rheumatic diseases. To test the hypothesis that SS autoantibodies (Abs) regulate VEGF-A/VEGFR2 expression by a TACE-dependent nuclear factor-κB (NF-κB) activation pathway, their effects on the expression and activation of the VEGF-A/TACE/VEGFR2/NF-κB pathway were determined in human salivary gland epithelial cells (SGEC). An enhanced angiogenesis in SS salivary gland biopsies was observed, associated with an increased VEGF-A expression and activation of VEGF-A/VEGFR2 signaling. Human cytokine array analysis of the pro-inflammatory and pro-angiogenic protein response in SGEC treated with SS Abs revealed an overexpression of multiple pro-angiogenic factors. TACE RNA knockdown, the use of anti-VEGF-A monoclonal antibody and the inhibition of NF-κB activity significantly abrogated the release of pro-angiogenic factors, demonstrating that VEGF-A/TACE/VEGFR2/NF-κB axis dysfunction may be contributory to pathogenesis and exacerbation of this autoimmune condition.

Nanotherapeutic approaches for the treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is a common inflammatory disease characterized by progressive bone and cartilage destruction, resulting in severe functional limitations, shortened lifespan, and increased mortality rates. Recent advances and new treatment approaches have significantly delayed disease progression and improved the quality of life for many patients. Yet few patients attain or can be maintained in disease remission without continuous immunosuppressive therapy. In addition, a sizable portion of patients also fails to respond or eventually develops tolerance to current therapies. Thus there is a continued need for the development of new therapeutic strategies for the treatment of RA. Unlike conventional drugs, nanosystems are designed to deliver therapeutic agents specifically to the site of inflammation, therefore avoiding potential systemic and off-target unwanted effects. They allow investigators to consider or reconsider therapeutic agents that were previously deemed too toxic to deliver through a systemic route. This article reviews recent nanotechnology-based strategies that are being developed for the treatment of inflammatory arthritis.

Tacrolimus (FK506) inhibits interleukin-1β-induced angiopoietin-1, Tie-2 receptor, and vascular endothelial growth factor through down-regulation of JNK and p38 pathway in human rheumatoid fibroblast-like synoviocytes

OBJECT

This study aimed to identify the regulatory effect of tacrolimus on the interleukin-1β (IL-1β)-induced expressions of angiopoietin-1 (Ang-1), Tie-2 receptor (Tie-2), and vascular endothelial growth factor (VEGF) in human rheumatoid fibroblast-like synoviocytes (FLS) and to determine the regulatory mechanism in the mitogen-activated protein kinases (MAPKs) signaling pathway.

METHODS

IL-1β-induced Ang-1, Tie-2, and VEGF expressions with and without tacrolimus were measured in cultured FLS using real time-polymerase chain reaction, enzyme-linked immunosorbent assay, Western blotting, and immunofluorescence staining. The effect of tacrolimus on the regulation of Ang-1, Tie-2 and VEGF expressions through the MAPK signaling pathway was identified by Western blotting and immunofluorescence staining.

RESULTS

IL-1β appeared to induce marked expressions of Ang-1, Tie-2, and VEGF in cultured FLS. Tacrolimus significantly inhibited Ang-1, Tie-2, and VEGF mRNA and protein in cultured FLS treated with 10 ng/ml IL-1β. In addition, expressions of these angiogenic molecules were shown to involve all three of the studied MAPK signaling pathways, including ERK, JNK, and p38. However, the inhibitory effects of tacrolimus on Ang-1, Tie-2, and VEGF proteins were regulated by blocking the phosphorylations of JNK and p38 MAPK, but not that of ERK.

CONCLUSION

This study demonstrates that tacrolimus inhibits the expressions of Ang-1, Tie-2, and VEGF by blocking the activations of the IL-1β-mediated JNK and p38 MAPK pathways in human FLS. This suggests that tacrolimus contributes to the suppression of angiogenesis in the pathogenesis of RA.

The vasculature in rheumatoid arthritis: cause or consequence?

The expansion of the synovial lining of joints in rheumatoid arthritis (RA) necessitates an increase in the vascular supply to the synovium, to cope with the increased requirement for oxygen and nutrients. New blood vessel formation -'angiogenesis'- is recognized as a key event in the formation and maintenance of the pannus in RA, suggesting that targeting blood vessels in RA may be an effective future therapeutic strategy. Although many pro-angiogenic factors have been demonstrated to be expressed in RA synovium, vascular endothelial growth factor (VEGF) has been demonstrated to a have a central involvement in the angiogenic process in RA. Nevertheless, it is unclear whether angiogenesis - whether driven by VEGF and/or other factors - should be considered as a 'cause' or 'consequence' of disease. This ongoing 'chicken vs. egg' debate is difficult, as even the success of angiogenesis inhibition in models of RA does not provide a direct answer to the question. This review will focus on the role of the vasculature in RA, and the contribution of different angiogenic factors in promoting disease. Although no data regarding the effectiveness of anti-angiogenic therapy in RA have been reported to date, the blockade of angiogenesis nevertheless looks to be a promising therapeutic avenue.

Angiogenesis as a therapeutic target in arthritis: learning the lessons of the colorectal cancer experience

The idea of a therapeutic modality aimed at 'starving' a tissue of blood vessels, and consequentially of oxygen and nutrients, was born from the concept that blood vessel formation (angiogenesis) is central to the progression and maintenance of diseases which involve tissue expansion/invasion. In the first instance, solid malignancies were the target for anti-angiogenic treatments, with colorectal cancer being the first disease for which an angiogenesis inhibitor--anti-vascular endothelial growth factor antibody bevacizumab--was approved in 2004. Our understanding of the pathogenesis of rheumatoid arthritis (RA) has lead to many parallels being drawn between this chronic inflammatory disease and solid tumours, in that both involve tissue expansion, invasion, expression of cytokines and growth factors and areas of hypoxia/hypoperfusion. As a result, angiogenesis blockade has been touted as a possible treatment for RA. The lessons learnt during the progression of eventually successful therapies such as bevacizumab should undoubtedly guide us in the future development of comparable treatments for RA.

[Angiogenesis. Possibilities for therapeutic intervention in rheumatic diseases]

In contrast to vasculogenesis, angiogenesis is defined as the formation of new vessels from preexisting ones. Physiologically, this multistep process occurs in adults during the reproductive cycle and during pregnancy, pathophysiologically it can be found in wound healing, inflammation and carcinogenesis. The underlying mechanisms are vasodilatation and increasing permeability, destabilization of vessel walls and degradation of extracellular matrix, followed by the proliferation and migration of endothelial cells. Migrated endothelial cells form vascular tubes at sites of ischemia and these tubes are finally stabilized by pericytes and smooth muscle cells. This process is controlled by a complex interaction of angiogenic and angiostatic factors. In contrast to carcinogenesis, the role of angiogenesis for the pathogenesis and therapy of rheumatic diseases is less understood. Two examples for pathologically disturbed angiogenesis, rheumatoid arthritis and systemic sclerosis, are discussed in this review with respect to therapeutic options.

Amelioration of collagen-induced arthritis in rats by nanogold

OBJECTIVE

Angiogenesis plays a part in the pathogenesis of rheumatoid arthritis (RA), and nanogold inhibits the activity of an angiogenic factor, vascular endothelial growth factor (VEGF). We therefore investigated whether intraarticular delivery of nanogold ameliorates collagen-induced arthritis (CIA) in rats.

METHODS

Binding of 13-nm nanogold to VEGF in human RA synovial fluid (SF) and its effects on RA SF-induced endothelial cell proliferation and migration were assessed. Nanogold was administered intraarticularly to rats with CIA before the onset of arthritis. Progression of CIA was monitored by measures of clinical, radiologic, and histologic changes. In addition, the microvessel density and extent of infiltrating macrophages as well as levels of tumor necrosis factor alpha (TNFalpha) and interleukin-1beta (IL-1beta) in the ankle joints were determined.

RESULTS

Nanogold bound to VEGF in RA SF, resulting in inhibition of RA SF-induced endothelial cell proliferation and migration. Significant reductions in ankle circumference, articular index scores, and radiographic scores were observed in the nanogold-treated rats with CIA compared with their control counterparts. In addition, the histologic score (of synovial hyperplasia, cartilage erosion, and leukocyte infiltration), microvessel density, macrophage infiltration, and levels of TNFalpha and IL-1beta were also significantly reduced in the ankle joints of nanogold-treated rats.

CONCLUSION

Our results are the first to demonstrate that intraarticular administration of nanogold ameliorates the clinical course of CIA in rats. Nanogold exerted antiangiogenic activities and subsequently reduced macrophage infiltration and inflammation, which resulted in attenuation of arthritis. These results demonstrate proof of principle for the use of nanogold as a novel therapeutic agent for the treatment of RA.

Vascular Endothelial Growth Factor (VEGF) in Autoimmune Diseases

Vascular endothelial growth factor (VEGF) is a potent stimulating factor for angiogenesis and vascular permeability. There are eight isoforms with different and sometimes overlapping functions. The mechanisms of action are under investigation with emerging insights into overlapping pathways and cross-talk between other receptors such as the neuropilins, which were not previously associated to angiogenesis. VEGF has important physiological actions on embryonic development, healing, and menstrual cycle. It also has a great role in pathological conditions that are associated to autoimmune diseases. There is considerable evidence in various autoimmune diseases such as in systemic lupus erythematosus, rheumatoid arthritis, and multiple sclerosis of an interrelationship between the VEGF system and theses disorders. Serum levels of VEGF correlate with disease activity in a large number of autoimmune diseases and fall with the use of standard therapy. We raised the possible future therapeutic strategies in autoimmune diseases with the anti-VEGF or anti-VEGFR (receptor). So far, this therapy has been used in cancer and macular ocular degeneration in diabetes. This review outlines the evidence for VEGF participation in various autoimmune diseases and proposes lines for future research in this field.

Inhibitory effect of bucillamine on the increased leukocyte entrapment in the retinal microcirculation of diabetic rats

PURPOSE

To evaluate quantitatively the effects of bucillamine on the entrapment of leukocytes in the retinal microcirculation of diabetic rats.

METHODS

13 male Brown Norway rats were injected with streptozotocin (STZ). After the animals developed diabetes, they were divided into two groups. Group 1 (n=7) received fresh drinking water without bucillamine, and group 2 (n=6) received fresh drinking water supplemented with bucillamine (200 mg/kg per day). Rats that were not injected with STZ and received water without bucillamine served as controls (n=6). Four weeks after the injection of STZ, the leukocytes in the retina were observed by acridine orange digital fluorography. The number of leukocytes trapped in the retinal vessels was compared among the three groups.

RESULTS

In the untreated diabetic rats, the number of trapped leukocytes was significantly higher than in control rats or bucillamine-treated diabetic rats (P<0.05).

CONCLUSIONS

We demonstrated an inhibitory effect of bucillamine on leukocyte entrapment in the retinal vessels of diabetic rats. Bucillamine may have therapeutic efficacy in preventing the development of diabetic retinopathy.

Power Doppler assessment of overall disease activity in patients with rheumatoid arthritis

PURPOSE

To examine synovial vascularity and flow patterns in hand and wrist joints--metacarpophalangeal (MCP) joints and ulnar stiloid (USTL) regions--of patients with rheumatoid arthritis (RA) using power Doppler sonography (PDUS) and spectral Doppler analysis and to assess the accuracy of PDUS in detecting overall disease activity in RA patients.

METHODS

Two hundred forty MCP joints and 48 USTL regions in 24 RA patients were examined. Patients were categorized into 2 groups--active and inactive--according to the American College of Rheumatology remission criteria. Resistance indexes (RIs) were measured.

RESULTS

Flow signals were detected in 50 MCP joints (in 13 patients) and 24 USTL regions (in 16 patients) and spectral analysis was performed in 46 MCP joints (12 patients) and 23 USTL regions (16 patients). The sensitivity and specificity of PDUS in detecting disease activity in RA were 92% and 40%, respectively. There was a negative correlation between flow signal number and RI, with higher scores of flow signals corresponding to lower RIs.

CONCLUSION

PDUS appears to be a reliable method for assessing inflammatory activity in rheumatoid synovium.

Changes in serum fibroblast growth factor 2 in patients with glucocorticoid-induced osteoporosis treated with human parathyroid hormone (1-34)

Since the ability of parathyroid hormone (PTH) to increase osteoblast maturation and activity is associated with basic fibroblast growth factor (bFGF) we determined the changes in serum bFGF levels in patients treated with human parathyroid hormone (hPTH) (1-34) for 12 months and 12 months follow up. All studied subjects (n=51) had postmenopausal osteoporosis, had been receiving long-term treatment with glucocorticoid plus estrogen or estrogen/progesterone and were randomly allocated either to a group receiving hPTH, 400 U/day (n=28), or to a control group (n=23). Osteocalcin (OST), bone-specific alkaline phosphatase (BSAP) and bFGF were monitored at the baseline, every 3 months for 18 months, and at 24 months. In the hPTH group, OST increased by more than 150% above baseline at 3 months and was maintained at this level throughout the treatment period. BSAP had increased more than 80% over the baseline level at 3 months and was maintained at 90% above baseline for the next 9 months. bFGF levels had increased by 45% at 3 months, 60% at 6 to 9 months (P<0.05) and had increased more than 90% from baseline by 12 months (P<0.05). We found that daily hPTH injections increased bFGF levels. These results support the hypothesis that up-regulation of bFGF could play a role in the osteoblastic response to PTH.

Suppression of laser-induced choroidal neovascularization by oral administration of SA3443 in mice

The effect of a synthetic cyclic disulfide compound, SA3443, on neovascularization was investigated. In vitro, enzyme-linked immunosorbent assay and RT-PCR demonstrated that SA3443 suppressed the expression of the hypoxia-induced vascular endothelial growth factor (VEGF) at both protein and mRNA levels in ARPE-19 cells. In vivo, the administration of SA3443 to mice with laser-induced choroidal neovascularization (CNV) suppressed the leakage from the lesions and reduced their size. Furthermore, the expression level of VEGF protein was significantly reduced by the administration of SA3443. Taken together, our results demonstrate that SA3443 suppresses VEGF production and reduces vascular leakage and the growth of mouse experimental CNV.

Effects of combination M40403 and dexamethasone therapy on joint disease in a rat model of collagen-induced arthritis

OBJECTIVE

To investigate the effects of combination therapy with M40403, a superoxide dismutase mimetic (SODm), and dexamethasone (DEX) on collagen-induced arthritis (CIA) in rats.

METHODS

CIA was elicited in Lewis rats by an intradermal injection of 100 mul of an emulsion of bovine type II collagen (CII) in Freund's incomplete adjuvant (IFA) at the base of the tail. On day 21, a second injection of CII in IFA was administered at the base of the tail.

RESULTS

Lewis rats developed erosive arthritis of the hind paw when immunized with an emulsion of CII in IFA. The histopathology of CIA included erosion of the articular cartilage at the joint margins and subchondral bone resorption. Immunohistochemical analysis for nitrotyrosine, poly(ADP-ribose) polymerase (PARP), inducible nitric oxide synthase (iNOS), and cyclooxygenase 2 (COX-2) revealed positive staining in inflamed joints of collagen-treated rats. The combination therapy with M40403 2 mg/kg and DEX 0.01 mg/kg significantly reduced the development of the inflammatory process and reduced the degree of staining for iNOS, COX-2, nitrotyrosine, and PARP. No significant difference in the degree of staining between the combination therapy and the higher dose of DEX (0.1 mg/kg) was found. Furthermore, radiographic evidence of protection from bone resorption was apparent in the tibiotarsal joints of rats that received the combination therapy.

CONCLUSION

This study shows that combination therapy with M40403 and DEX reduced the degree of chronic inflammation and tissue and bone damage associated with CIA in the rat. It supports the possible use of SODm in combination with steroids to reduce the dose necessary and the side effects related to the use of steroids in the management of chronic diseases such as rheumatoid arthritis.

Hypoxia and angiogenesis in rheumatoid arthritis

PURPOSE OF REVIEW

Angiogenesis is a prominent feature of rheumatoid synovitis. Although new blood vessels deliver oxygen to the augmented inflammatory cell mass, the neovascular network is dysfunctional and fails to restore tissue oxygen homeostasis, so that the rheumatoid joint remains a markedly hypoxic environment. The purpose of this review is to discuss the role of hypoxia and angiogenesis in the pathogenesis of rheumatoid arthritis.

RECENT FINDINGS

Vascular pathologic change, in the form of angiogenesis, is important in the perpetuation of rheumatoid arthritis and, in the form of endothelial dysfunction, contributes to associated cardiovascular comorbidity. Recent data suggest that tumor necrosis factor-alpha blockade may modify the vascular pathologic changes in rheumatoid arthritis. Angiogenesis is a prominent feature of rheumatoid synovitis. Emerging evidence based on ultrasonographic vascular imaging and angiogenic biomarkers implicates angiogenesis in the active phase of erosive disease. Many factors contribute to the profoundly hypoxic environment that can arise within the joint affected by rheumatoid arthritis. At a cellular level, hypoxia is detected by a mechanism that regulates cytoplasmic concentrations of hypoxia-inducible factor-1alpha. After translocation to the nucleus, hypoxia-inducible factor-1alpha binds its partner hypoxia-inducible factor-1beta to form a heterodimeric, functional transcription factor, hypoxia-inducible factor-1, which activates a gene program associated with angiogenesis, glycolysis, and adaptation to pH.

SUMMARY

Despite the luxuriant vasculature associated with rheumatoid arthritis synovitis, the joint affected by rheumatoid arthritis is hypoxic. Repetitive cycles of hypoxia and reoxygenation together with oxidants produced by phagocytic cells promote chronic oxidative stress within the microenvironment of the affected joint, leading to the generation of reactive oxygen species with the potential to contribute to tissue damage.

A comparison between povidone-ethylcellulose and povidone-eudragit transdermal dexamethasone matrix patches based on in vitro skin permeation

The present study was designed to develop a suitable matrix type transdermal drug delivery system (TDDS) of dexamethasone using blends of two different polymeric combinations, povidone (PVP) and ethylcellulose (EC) and Eudragit with PVP. Physical studies including moisture content, moisture uptake, flatness to study the stability of the formulations and in vitro dissolution of the experimental formulations were performed to determine the amount of dexamethasone present in the patches were performed and scanning electron microscopy (SEM) photographs of the prepared TDDS were taken to see the drug distribution pattern. Drug-excipient interaction studies were carried out using Fourier transform infrared (FTIR) spectroscopic technique. In vitro skin permeation study was conducted in a modified Franz's diffusion cell. All the formulations were found to be suitable for formulating in terms of physicochemical characteristics and there was no significant interaction noticed between the drug and polymers used. In vitro dissolution studies showed that the drug distribution in the matrix was homogeneous and the SEM photographs further demonstrated this. The formulations of PVP:EC provided slower and more sustained release of drug than the PVP:Eudragit formulations during skin permeation studies and the formulation PVP:EC (1:5) was found to provide the slowest release of drug. Based on the above observations, it can be reasonably concluded that PVP-EC polymers are better suited than PVP-Eudragit polymers for the development of TDDS of dexamethasone.

Anti-TNF-α antibody Infliximab and glucocorticoids reduce serum vascular endothelial growth factor levels in patients with rheumatoid arthritis: a pilot study

To compare the effect of oral glucocorticoid (GC) therapy with the effect of intravenous anti-TNF-alpha-therapy on serum VEGF levels of patients with rheumatoid arthritis (RA). Five RA patients (5/8) who had no prior treatment with DMARDs (Disease modifying antirheumatic drugs) or GCs were administered 20 mg prednisolone daily. Three patients who failed more than one DMARD therapy received infusion with Infliximab (200 mg). VEGF-serum levels were measured by enzyme-linked immunosorbent assay before treatment,and at day 10 or 13 during prednisolone therapy, or 14 days after the first Infliximab infusion. Serum VEGF levels in therapy naive RA patients (GC group) were higher than those in pretreated patients who received Infliximab (median serum VEGF level: 1106 vs 320 pg/ml; P=0.1). Treatment with Infliximab as well as GCs significantly decreased serum VEGF levels after 10-14 days in RA patients (median serum VEGF level after treatment: GC group 559 pg/ml, Infliximab group 92 pg/ml; P=0.01 vs without treatment or preinfusion).

CONCLUSIONS

Anti-TNF-alpha antibody Infliximab as well as GC are able to decrease serum VEGF levels in patients with active RA. Whether therapeutic reduction of serum VEGF levels is associated with inhibition of angiogenesis should be evaluated in future by imaging of synovial vasculature.

Evaluation of metacarpophalangeal joint synovitis in rheumatoid arthritis by power Doppler technique: relationship between synovial vascularization and periarticular bone mineral density

OBJECTIVE

To evaluate intra-articular vascularization and flow patterns of the metacarpophalangeal (MCP) joints in rheumatoid arthritis (RA) patients by using power Doppler technique. The relationship between the flow patterns and the regional bone mineral density (BMD) measurements of MCP joints using dual-energy X-ray absorptiometry (DXA) was also assessed.

METHODS

Fifteen patients (mean age 48.5 +/- 13.8) with a disease duration of 6.8 +/- 4.9 years were included into the study. Thirty MCP joints of three healthy subjects were also assessed as controls. Clinical activity of MCP joint inflammation was classified according to a modified index for synovitis activity based on joint swelling, warmness and pain. Ultrasonography was performed using LOGIQ 7 unit by means of a 6-13 MHz linear array transducer. Gray-scale US and power Doppler sonography (PDS) examination was performed. Using spectral Doppler the quality of flow was determined and the indices of pulsatility (PI) and resistance (RI) were measured in longitudinal plane. The erosive scores of the MCP joints were determined on the plain hand radiographs using Sharp/van der Heijde method. Hand BMD, MCP BMD and the ratio of MCP BMD to whole hand BMD (rBMD) were measured using a Lunar DPX densitometer.

RESULTS

Total 150 MCP joints of 15 patients and 30 MCP joints of three healthy controls were examined in both hands. Flow was determined in 31 joints (10 moderately active, 21 active) in eight patients whereas seven patients had no quantifiable flow in MCP joints. MCP joints of healthy controls had no quantifiable flow. Mean PI of these joints were 2.17 +/- 2.37 in moderately active and 2.12 +/- 1.93 in active MCP joints. RI was 0.76 +/- 0.12 in moderately active and 0.75 +/- 0.15 in active MCP joints. There was no significant difference in RI and PI of these active and moderately active MCP joints. There was a significant correlation between erosive scores and PI, RI of total MCP joints (r = 0.40 and r = 0.41, P < 0.05). PI and RI also negatively correlated with rBMD (r = -0.46, P < 0.01 and r = -0.36, P < 0.05, respectively). PIc was 4.07 +/- 3.26 and RIc was 0.88 +/- 0.16 in the neighboring soft tissues which were significantly higher than PI and RI of MCP joints (P < 0.001).

CONCLUSION

Power Doppler ultrasonography (PDUS) is a useful method demonstrating synovial vascularization and flow patterns and offers new alternatives for monitoring disease activity and measurement of therapeutic response. Flow patterns had intimate correlation with intra-articular bone and cartilage destruction.

Serum vascular markers and vascular imaging in assessment of rheumatoid arthritis disease activity and response to therapy

Vascular pathology, in the form of angiogenesis, is important in the perpetuation of rheumatoid arthritis (RA) and, in the form of endothelial dysfunction, contributes to associated cardiovascular co-morbidity. Emerging evidence suggests that TNFalpha blockade may modify vascular pathology in RA. Serum concentrations of vascular endothelial growth factor (VEGF), a potent endothelial cell-specific growth factor that is up-regulated by pro-inflammatory cytokines and by hypoxia, are elevated in RA and correlate with disease activity. Serum levels of VEGF at first presentation in RA predict radiographic progression of the disease over the subsequent year. Power Doppler ultrasonography is a sensitive method for demonstrating the presence of blood flow in small vessels and the vascular signal correlates with histopathological quantification of the vascular density of synovial tissue. Recent data indicate that high-frequency ultrasound and power Doppler are sensitive tools for evaluation of disease activity and assessment of response to therapy. Power Doppler imaging may also have the potential to predict those patients most at risk of accelerated joint destruction. However, much work has yet to be done to standardize the use of these imaging technologies.

Dexamethasone delays ulcer healing by inhibition of angiogenesis in rat stomachs

Using the non-ulcerogenic doses of dexamethasone, we explored the action of glucocorticoids on ulcer healing and its relationship with angiogenic factors in the gastric mucosa. We applied dexamethasone (0.1 or 0.2 mg/kg/day) intragastrically in rats with acetic acid-induced gastric ulcer. The mucosal prostaglandin E(2) level and protein expressions of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) at the ulcer margin were determined. Ulcer induction significantly increased protein expressions of bFGF, VEGF, and prostaglandin E(2) level at the ulcer margin together with angiogenesis at the ulcer margin and base. The non-ulcerogenic doses of dexamethasone inhibited angiogenesis at the ulcer margin and ulcer base and delayed ulcer healing. These were associated with a significant decrease of prostaglandin E(2) level and VEGF expression, but not the bFGF expression. Supplementation with prostaglandin E(2) attenuated the inhibitory action of dexamethasone on VEGF expression and reversed the adverse effects of dexamethasone on angiogenesis and ulcer healing, without influencing bFGF expression. We concluded that dexamethasone given at non-ulcerogenic doses could decrease angiogenesis and delay acetic acid-induced ulcer healing; these actions were at least, in part, due to depletion of prostaglandin E(2) level followed by down-regulation of VEGF at the ulcer margin of the stomach.

A methionine aminopeptidase-2 inhibitor, PPI-2458, for the treatment of rheumatoid arthritis

The hallmark of rheumatoid arthritis (RA) is the progressive destruction of articular joints, characterized by invasive synovial hyperplasia and pathological neovascularization. Here we report that PPI-2458, a member of the fumagillin class of irreversible methionine aminopeptidase-2 (MetAP-2) inhibitors, potently inhibits the proliferation of human fibroblast-like synoviocytes (HFLS-RA), derived from RA patients, with a growth inhibitory concentration 50 (GI(50)) of 0.04 nM and a maximum inhibition of >95% at 1 nM. Human umbilical vein endothelial cells (HUVEC) are similarly inhibited in proliferation by PPI-2458 (GI(50), 0.2 nM). We developed a method to measure the level of MetAP-2 enzyme inhibition after exposure to PPI-2458 and demonstrate that growth inhibition of PPI-2458-sensitive HFLS-RA and HUVEC is linked to MetAP-2 enzyme inhibition, in a dose-dependent fashion. The secretion of several inflammatory mediators such as IL-6 and vascular endothelial growth factor from activated HFLS-RA was not inhibited by PPI-2458. The CNS toxicity profile of PPI-2458, determined by the incidence of seizures, is significantly improved over that of the parental compound TNP-470. In the rat model of peptidoglycan-polysaccharide-induced arthritis, PPI-2458 significantly attenuated paw swelling when therapeutically administered after the onset of chronic disease. We suggest that the mechanism of PPI-2458 action, highly selective and potent anti-proliferative activity on HFLS-RA and HUVEC in vitro, a significantly improved CNS toxicity profile, and marked attenuation of chronic disease in the rat peptidoglycan-polysaccharide arthritis model in vivo, positions this compound as a drug for the treatment of RA.

Increased vascular endothelial growth factor production in fibroblasts isolated from strictures in patients with Crohn's disease

BACKGROUND

Vascular endothelial growth factor (VEGF) is a potent angiogenic factor that is implicated in early wound healing and fibrosis. Fibroblasts may initiate stricture formation in Crohn's disease through overexpression of VEGF. The aim of this study was to examine VEGF expression and regulation in fibroblasts isolated from patients with Crohn's disease.

METHODS

Fibroblasts were isolated by a primary explant technique from serosal biopsies of non-strictured and strictured segments of bowel from eight patients undergoing resection for Crohn's disease, and normal colon from six patients undergoing resection for benign and malignant colorectal disease. Fibroblasts were cultured with transforming growth factor (TGF) beta and corticosteroids. After 24 h the culture supernatant was collected for VEGF assay by enzyme-linked immunosorbent assay.

RESULTS

VEGF production was significantly higher in fibroblasts isolated from strictures (mean(s.e.m.) 1980(260) pg/ml) than from non-strictured segments (1116(165) pg/ml) in patients with Crohn's disease or control fibroblasts (898(93) pg/ml). TGF-beta increased VEGF production in normal and non-strictured Crohn's fibroblasts. Corticosteroids suppressed unstimulated VEGF production in all groups.

CONCLUSION

Enhanced serosal fibroblast VEGF production might play a role in initiating stricture formation in Crohn's disease. VEGF production in serosal fibroblasts is sensitive to stimulation with TGF-beta. Corticosteroids may reduce stricturing through suppression of VEGF.

Inhibitory effects of bucillamine on the expression of vascular cell adhesion molecule-1 in human umbilical vein endothelial cells

Bucillamine (BUC) has been found to have beneficial effects in the treatment of rheumatoid arthritis (RA), in which the activation of endothelial cells plays an important role in the pathogenesis. The current studies examined the effect of BUC and its intramolecular disulfide form (BUC-ID) on the expression of adhesion molecules in human umbilical vein endothelial cells (HUVEC) stimulated with tumor necrosis factor-alpha (TNF-alpha). HUVEC (4 x 10(4)/well) were incubated with medium M199 containing heparin and 20% FCS with endothelial cell growth supplement (ECGS) for 24 h in the presence or absence of BUC or BUC-ID, after which the culture medium was replaced with ECGS free medium. Then the cultures were further carried out for additional 24 h with TNF-alpha (10 ng/ml) in the presence or absence of BUC or BUC-ID. BUC-ID, but not BUC, appeared to suppress the expression of VCAM-1 on HUVEC stimulated with TNF-alpha in a dose-response manner at its pharmacologically relevant concentrations (0.3-3.0 microg/ml), whereas only the 3 microg/ml concentration level of BUC-ID had a statistically significant effect, although the effect was relatively small. By contrast, lower concentrations of BUC-ID (1-3 microg/ml) suppressed the secretion of soluble VCAM-1 by HUVEC much more effectively. Of note, at the concentration of 3 microg/ml neither BUC nor BUC-ID significantly influenced the expression of ICAM-1 and E-selectin on TNF-alpha stimulated HUVEC. These results indicate that BUC-ID, but not BUC, specifically downregulates the surface expression of VCAM-1 as well as the release of soluble VCAM-1 by HUVEC stimulated with TNF-alpha. BUC-ID suppressed the production of solubleVCAM-1 by RA bone marrow CD34+ cells stimulated with SCF, GM-CSF and TNF-alpha more effectively than BUC. The data thus suggest that one of the mechanisms of action of BUC involves the inhibition of the activation of endothelial cells.

The therapeutic potential of TNF-alpha blockade in rheumatoid arthritis

Rheumatoid arthritis is a chronic autoimmune disease characterised by inflammation of the synovial lining of joints and destruction of cartilage and bone. Many pro-inflammatory cytokines, chemokines and growth factors are expressed in diseased joints, and recognition of the key role of TNF-alpha led to the development of highly effective new therapies. TNF-alpha inhibitors, such as monoclonal anti-TNF-alpha antibody infliximab (Remicade), have demonstrated efficacy in clinical trials. It is now clear that TNF-alpha blockade, in addition to reducing joint inflammation and leukocyte infiltration, also results in decreased formation of new blood vessels in the synovium. Such mechanism of action studies are now paving the way for the development of the next generation of drugs for treatment of rheumatoid arthritis.

Distinct protein kinase C isoforms mediate regulation of vascular endothelial growth factor expression by A2A adenosine receptor activation and phorbol esters in pheochromocytoma PC12 cells

Vascular endothelial growth factor (VEGF) stimulates angiogenesis during development and in disease. In pheochromocytoma (PC12) cells, VEGF expression is regulated by A(2A) adenosine receptor (A(2A)AR) activation. The present work examines the underlying signaling pathway. The adenylyl cyclase-protein kinase A cascade has no role in the down-regulation of VEGF mRNA induced by the A(2A)AR agonist, 2-[4-[(2-carboxyethyl)phenyl]ethylamino]-5'-N-ethylcarboxamidoadenosine (CGS21680). Conversely, 6-h exposure of cells to either phorbol 12-myristate 13-acetate (PMA) or protein kinase C (PKC) inhibitors mimicked the CGS21680-induced down-regulation. PMA activated PKCalpha, PKCepsilon, and PKCzeta, and CGS21680 activated PKCepsilon and PKCzeta as assessed by cellular translocation. By 6 h, PMA but not CGS21680 decreased PKCalpha and PKCepsilon expression. Neither compound affected PKCzeta levels. Following prolonged PMA treatment to down-regulate susceptible PKC isoforms, CGS21680 but not PMA inhibited the cobalt chloride induction of VEGF mRNA. The proteasome inhibitor, MG-132, abolished PMA- but not CGS21680-induced down-regulation of VEGF mRNA. Phorbol 12,13-diacetate reduced VEGF mRNA levels while down-regulating PKCepsilon but not PKCalpha expression. In cells expressing a dominant negative PKCzeta construct, CGS21680 was unable to reduce VEGF mRNA. Together, the findings suggest that phorbol ester-induced down-regulation of VEGF mRNA occurs as a result of a reduction of PKCepsilon activity, whereas that mediated by the A(2A)AR occurs following deactivation of PKCzeta.

A mutation in a CD44 variant of inflammatory cells enhances the mitogenic interaction of FGF with its receptor

Synovial fluid cells from joints of rheumatoid arthritis (RA) patients express a novel variant of CD44 (designated CD44vRA), encoding an extra trinucleotide (CAG) transcribed from intronic sequences flanking a variant exon. The CD44vRA mutant was detected in 23 out of 30 RA patients. CD44-negative Namalwa cells transfected with CD44vRA cDNA or with CD44v3-v10 (CD44vRA wild type) cDNA bound FGF-2 to an equal extent via their associated heparan sulfate chains. However, Namalwa cells, immobilizing FGF-2 via their cell surface CD44vRA, bound substantially more soluble FGF receptor-1 (FGFR-1) than did Namalwa cells immobilizing the same amount of FGF-2 via their cell surface CD44v3-v10. The former cells stimulated the proliferation of BaF-32 cells, bearing FGFR-1, more efficiently than did the latter cells. Finally, isolated primary synovial fluid cells from RA patients expressing CD44vRA bound more soluble FGFR-1 to their cell surface-associated FGF-2 than did corresponding synovial cells expressing CD44v3-v10 or synovial cells from osteoarthritis patients. The binding of soluble FGFR-1 to RA synovial cells could be specifically reduced by their preincubation with Ab's against the v3 exon product of CD44. Hence, FGF-2 attached to the heparan sulfate moiety expressed by the novel CD44 variant of RA synovium cells exhibits an augmented ability to stimulate FGFR-1-mediated activities. A similar mechanism may foster the destructive inflammatory cascade not only in RA, but also in other autoimmune diseases.

Inhibitory effects of bucillamine on increased blood-retinal barrier permeability in streptozotocin-induced diabetic rats

PURPOSE

To investigate the effect of bucillamine for prevention of increasing blood-retinal barrier (BRB) permeability in streptozotocin (STZ)-induced diabetic rats.

METHODS

The groups included control and STZ-induced diabetic rats treated with or without bucillamine. Six months after intervention, the concentrations of reduced and oxidative glutathione (GSH and GSSG) in the retina were measured biochemically. In addition, vitreous fluorescein, which leaks from the vessels after intravenous injection of fluorescein sodium, was measured to evaluate BRB permeability. To evaluate the scavenging ability against the reactive oxygen species (ROS) in vitro, the second-order rate constant for the reaction of bucillamine with ROS was estimated from the kinetics based on the rate constant for the reaction of ROS.

RESULTS

The BRB permeability was significantly higher (p = 0.01) in diabetic rats not treated with bucillamine, and bucillamine inhibited the BRB permeability. The GSH concentration and the GSH/GSSG ratio in the retinas decreased in diabetic rats not treated with bucillamine; bucillamine inhibited the decrease of the GSH concentrations. The ROS scavenging activity of bucillamine was similar with that of GSH.

CONCLUSIONS

In diabetic retinas, oxidative stress might increase, which may be one of the causes of BRB breakdown. The antioxidant effects of bucillamine might take part in inhibition of increased permeability of the BRB in diabetes.

VEGF and imaging of vessels in rheumatoid arthritis

Angiogenesis is a prominent feature of rheumatoid synovitis. Formation of new blood vessels permits a supply of nutrients and oxygen to the augmented inflammatory cell mass and so contributes to perpetuation of joint disease. Vascular endothelial growth factor (VEGF) is a potent endothelial cell-specific growth factor that is upregulated by proinflammatory cytokines and by hypoxia. Serum VEGF concentrations are elevated in rheumatoid arthritis (RA) and correlate with disease activity. Furthermore, serum VEGF measured at first presentation in RA is highly significantly correlated with radiographic progression of disease over the subsequent year. Power Doppler ultrasonography is a sensitive method for demonstrating the presence of blood flow in small vessels and there is a very close relation between the presence or absence of vascular flow signal on power Doppler imaging and the rate of early synovial enhancement on dynamic gadolinium-enhanced magnetic resonance imaging (MRI) of joints with RA. Images obtained by both dynamic enhanced MRI and power Doppler ultrasonography correlate with vascularity of synovial tissue as assessed histologically. In early RA, there is a striking association between joint erosions assessed on high-resolution ultrasonography and vascular signal in power Doppler mode. Collectively, these findings implicate vascular pannus in the erosive phase of disease and strongly suggest that proangiogenic molecules such as VEGF are targets for novel therapies in RA. Animal model data supports this concept. It seems likely that serological and imaging measures of vascularity in RA will become useful tools in the assessment of disease activity and response to therapy.

Adenovirus-mediated gene transfer of urokinase plasminogen inhibitor inhibits angiogenesis in experimental arthritis

Plasmin is essential for metalloproteases activation, endothelial cell migration and degradation of the extracellular matrix. The process is common to neoangiogenesis pannus formation and cartilage degradation within arthritic joints. Since 80% of synovial cells express urokinase plasminogen activator receptor (uPAR), we investigated the inhibition of plasmin activation in a collagen-induced arthritis (CIA) mice model, by expressing a uPA/uPAR antagonist molecule (ATF) fused to human serum albumin (HSA) to extend its serum half-life. Overexpression was obtained with an adenoviral vector expressing the chimeric murine ATF-HSA. We showed that the genetic coupling did not significantly reduce the ability of the ATF moiety to interact with its receptor uPAR. The chimeric protein was detectable in the sera of injected mice 7 days following Ad-mATF-HSA injection, then decreased in parallel with the anti-HSA titer increase. Systemic Ad-mATF-HSA injection performed on day 25 following CIA induction decreased the incidence of arthritis and the severity of the disease. Moreover, synovial angiogenesis in arthritic paws was decreased after Ad-mATF-HSA gene transfer, as assessed by smooth muscle actin immunostaining. The preventive effect observed on arthritis was related to the decrease in angiogenesis, rather than inhibition of extracellular matrix degradation.

Angiogenesis in rheumatoid arthritis

The expansion of the synovial lining of joints in rheumatoid arthritis (RA) and the subsequent invasion by the pannus of underlying cartilage and bone necessitate an increase in the vascular supply to the synovium, to cope with the increased requirement for oxygen and nutrients. The formation of new blood vessels - termed 'angiogenesis' - is now recognised as a key event in the formation and maintenance of the pannus in RA. This pannus is highly vascularised, suggesting that targeting blood vessels in RA may be an effective future therapeutic strategy. Disruption of the formation of new blood vessels would not only prevent delivery of nutrients to the inflammatory site, but could also lead to vessel regression and possibly reversal of disease. Although many proangiogenic factors are expressed in the synovium in RA, the potent proangiogenic cytokine vascular endothelial growth factor (VEGF) has been shown to a have a central involvement in the angiogenic process in RA. The additional activity of VEGF as a vascular permeability factor may also increase oedema and hence joint swelling in RA. Several studies have shown that targeting angiogenesis in animal models of arthritis ameliorates disease. Our own study showed that inhibition of VEGF activity in murine collagen-induced arthritis, using a soluble VEGF receptor, reduced disease severity, paw swelling, and joint destruction. Although no clinical trials of anti-angiogenic therapy in RA have been reported to date, the blockade of angiogenesis - and especially of VEGF - appears to be a promising avenue for the future treatment of RA.

Serum matrix metalloproteinases and tissue inhibitors of metalloproteinases in different histological variants of rheumatoid synovitis

OBJECTIVE

Rheumatoid synovitis is characterized by an invasive and tissue-destructive infiltrate of lymphocytes, macrophages and synoviocytes. Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) produced by these cells are important in the remodelling of the articular tissues in rheumatoid arthritis (RA). The aim of this study was to explore whether the serum concentrations of MMPs and their inhibitors were correlated with the histological appearance of the disease.

METHODS

Tissue and serum samples were obtained from 37 patients with clinically active RA and 30 with osteoarthritis (OA). Morphological analysis allowed the division of RA synovial specimens into two distinct types. In 22 samples only diffuse infiltrates of mononuclear cells without further microanatomical organization were found. In 15 specimens we observed lymphocytic conglomerates with germinal centre-like structures. Serum concentrations of interstitial collagenase (MMP-1), stromelysin-1 (MMP-3), gelatinase B (MMP-9), TIMP-1 and TIMP-2 were measured with an ELISA technique.

RESULTS

Unique serum profiles of MMPs and TIMPs were identified in each of the two histological types of RA synovitis. The serum concentrations of MMP-1, MMP-3 and MMP-9 were higher in RA patients than in OA patients used as a control group (P<0.001 for all comparisons). These three MMPs dominated in the serum of RA patients with follicular synovitis compared with those with diffuse synovitis (P<0.05, P<0.01 and P<0.001 respectively). The analysis of the serum concentrations of TIMP-1 and TIMP-2 showed that their levels were also elevated in RA patients compared with OA patients (P<0.001 and P<0.01 respectively). Only TIMP-1 was found in a significantly higher concentration in the serum of RA patients with follicular synovitis than in those with diffuse synovitis (P<0.05). The serum concentrations of MMPs and TIMP-1 clearly identified patients with two different histological types of rheumatoid synovitis and with OA. Additionally, the analysis of clinical data showed that the rheumatoid disease in patients with follicular synovitis seemed to be more active than in those with diffuse synovitis.

CONCLUSION

The morphological appearance of rheumatoid synovitis and the serum MMP and TIMP-1 profile were correlated with the clinical activity of the disease, confirming the heterogeneity of RA. These associations also suggest that patients with different histological forms of RA might require different treatment regimens.

Does vascular endothelial growth factor in the rheumatoid synovium predict joint destruction? A clinical, radiological, and pathological study in 12 patients monitored for 10 years

OBJECTIVE

Synovial angiogenesis is at the epicenter of rheumatoid pannus development and is largely dependent on vascular endothelial growth factor (VEGF). We sought to determine whether the VEGF level in rheumatoid synovial tissue is a marker for disease severity.

PATIENTS AND METHODS

Twelve patients with rheumatoid arthritis (RA) underwent a clinical and radiological evaluation at the time of a synovial biopsy done during joint surgery required by RA progression (T1) and, on average, 10 years later (T2). Immunohistochemistry was used to detect and quantitate VEGF in the synovial biopsy taken at T1.

RESULTS

VEGF labeling was seen on endothelial cells and macrophages in all 12 synovial biopsies. The amount of endothelial-cell VEGF labeling (assessed semi-quantitatively) was significantly correlated with Larsen score progression during the 10-year follow-up. The amounts of endothelial cell or macrophage VEGF labeling was not correlated with the joint count, radiological stage of the biopsied joint or progression of this stage, Larsen scores at T1 or T2, presence of rheumatoid factor, or presence of extra-articular manifestations.

CONCLUSION

Our results suggest that the amount of VEGF in the rheumatoid synovium may be a marker for joint destruction in patients with RA.

Raised serum vascular endothelial growth factor levels are associated with destructive change in inflammatory arthritis

OBJECTIVE

To determine whether elevated levels of the angiogenic cytokine vascular endothelial growth factor (VEGF), detected on presentation to an early arthritis clinic, are associated with the development of chronic and erosive arthritis.

METHODS

Concentrations of VEGF and its soluble receptor, soluble fms-like tyrosine kinase 1 (sFlt-1), were measured by enzyme-linked immunosorbent assay in serum samples from patients with early (<2 years from onset) arthritic symptoms in the peripheral joints, namely early rheumatoid arthritis (RA), self-limiting arthritis (viral, reactive, and idiopathic inflammatory arthritis), or psoriatic arthritis. In addition, measurements were made in random samples from patients with longstanding (>3 years from symptom onset) RA treated with disease-modifying antirheumatic drugs, from patients with osteoarthritis (OA), and from patients with polyarthralgia without arthritis, as well as from nonarthritic controls.

RESULTS

Serum VEGF levels at presentation were elevated in patients with inflammatory arthritis (RA, psoriatic, and self-limiting arthritis) as well as in patients with OA, in comparison with nonarthritic controls. Moreover, serum VEGF concentrations were significantly higher in patients with early RA than in patients with self-limiting arthritis. Serum VEGF levels at presentation in patients with early RA correlated significantly with the development of radiographic damage after 1 year. Improvement in the clinical symptoms of RA was associated with a reduction in serum VEGF levels. Serum sFlt-1 levels were raised in patients with early and longstanding RA and in those with self-limiting arthritis, and correlated positively with the serum VEGF concentrations in patients with inflammatory arthritis.

CONCLUSION

These findings implicate the proangiogenic cytokine VEGF in the persistence of inflammatory arthritis, and support the hypothesis that expansion of the synovial vasculature is important for the development of joint destruction in RA.