Prevention of cytokine-induced changes in leukocyte adhesion receptors by nonsteroidal antiinflammatory drugs from the oxicam family

NSAIDs do not reduce severity among post-ERCP pancreatitis patients

OBJECTIVE

Non-steroidal anti-inflammatory drugs (NSAIDs) are the most studied chemoprophylaxis for post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP). While previous systematic reviews have shown NSAIDs reduce PEP, their impact on moderate to severe PEP (MSPEP) is unclear. We conducted a systematic review and meta-analysis to understand the impact of NSAIDs on MSPEP among patients who developed PEP. We later surveyed physicians' understanding of that impact.

DESIGN

A systematic search for randomized trials using NSAIDs for PEP prevention was conducted. Pooled-prevalence and Odds-ratio of PEP, MSPEP were compared between treated vs. control groups. Analysis was performed using R software. Random-effects model was used for all variables. Physicians were surveyed via email before and after reviewing our results.

RESULTS

7688 patients in 25 trials were included. PEP was significantly reduced to 0.598 (95%CI, 0.47-0.76) in the NSAIDs group. Overall burden of MSPEP was reduced among all patients undergoing ERCP: OR 0.59 (95%CI, 0.42-0.83). However, NSAIDs didn't affect the proportion of MSPEP among those who developed PEP (p = 0.658). Rectal Indomethacin and diclofenac reduced PEP but not MSPEP. Efficacy didn't vary by risk, timing of administration, or bias-risk. Survey revealed a change in the impression of the effect of NSAIDs on MSPEP after reviewing our results.

CONCLUSIONS

Rectal diclofenac or indomethacin before or after ERCP reduce the overall burden of MSPEP by reducing the pool of PEP from which it can arise. However, the proportion of MSPEP among patients who developed PEP is unaffected. Therefore, NSAIDs prevent initiation of PEP, but do not affect severity among those that develop PEP. Alternative modalities are needed to reduce MSPEP among patients who develop PEP.

Looking at NSAIDs from a historical perspective and their current status in drug repurposing for cancer treatment and prevention

Non-steroidal anti-inflammatory drugs (NSAIDs) are one of the most frequently prescribed drug classes with wide therapeutic applications over the centuries. Starting from the use of salicylate-containing willow leaves to the recent rise and fall of highly selective cyclooxygenase-2 (COX-2) inhibitors and the latest dual-acting anti-inflammatory molecules, they have displayed a rapid and ongoing evolution. Despite the enormous advances in the last twenty years, investigators are still in search of the design and development of more potent and safer therapy against inflammatory conditions. This challenge has been increasingly attractive as the emergence of inflammation as a common seed and unifying mechanism for most chronic diseases. Indeed, this fact put the NSAIDs in the spotlight for repurposing against inflammation-related disorders. This review attempts to present a historical perspective on the evolution of NSAIDs, regarding their COX-dependent/independent mode of actions, structural and mechanism-based classifications, and adverse effects. Additionally, a systematic review of previous studies was carried out to show the current situation in drug repurposing, particularly in cancers associated with the GI tract such as gastric and colorectal carcinoma. In the case of non-GI-related cancers, preclinical studies elucidating the effects and modes of action were collected and summarized.

British Association of Sexual Health and HIV national guideline on the management of sexually acquired reactive arthritis 2021

These guidelines update the 2008 UK guideline for the management of sexually acquired reactive arthritis. The guideline is aimed at those over the age of 16 years, presenting to healthcare professionals working in sexual health services. The recommendations are primarily aimed at services offering level 3 care in sexually transmitted infection management within the United Kingdom. However, the principles will apply to those presenting to level 1 and 2 services, and appropriate local referral pathways will need to be developed.

G Protein-Coupled Estrogen Receptor 1 Regulates Human Neutrophil Functions

Background

The role of estrogens in immune functioning is relatively well known under both physiological and pathological conditions. Neutrophils are the most abundant circulating leukocytes in humans, and their abundance and function are regulated by estrogens, since they express estrogen receptors (ERs). Traditionally, estrogens were thought to act via classical nuclear ERs, namely ERα and ERβ. However, it was observed that some estrogens induced biological effects only minutes after their application. This rapid, "nongenomic" effect of estrogens is mediated by a membrane-anchored receptor called G protein-coupled estrogen receptor 1 (GPER1). Nevertheless, the expression and role of GPER1 in the immune system has not been exhaustively studied, and its relevance in neutrophil functions remains unknown.

Methods

Human neutrophils were incubated in vitro with 10-100 µ<smlcap>M</smlcap> of the GPER1-specific agonist G1 alone or in combination with lipopolysaccharide. GPER1 expression and subcellular localization, respiratory burst, life span, gene expression profile, and cell signaling pathways involved were then analyzed in stimulated neutrophils.

Results

Human neutrophils express a functional GPER1 which regulates their functions through cAMP/protein kinase A/cAMP response element-binding protein, p38 mitogen-activated protein kinase, and extracellular regulated MAPK signaling pathways. Thus, GPER1 activation in vitro increases the respiratory burst of neutrophils, extends their life span, and drastically alters their gene expression profile.

Conclusions

Our results demonstrate that GPER1 activation promotes the polarization of human neutrophils towards a proinflammatory phenotype and point to GPER1 as a potential therapeutic target in immune diseases where neutrophils play a key role.

The role of MyD88- and TRIF-dependent signaling in monophosphoryl lipid A-induced expansion and recruitment of innate immunocytes

Treatment with the TLR4 agonist MPLA augments innate resistance to common bacterial pathogens. However, the cellular and molecular mechanisms by which MPLA augments innate immunocyte functions are not well characterized. This study examined the importance of MyD88- and TRIF-dependent signaling for leukocyte mobilization, recruitment, and activation following administration of MPLA. MPLA potently induced MyD88- and TRIF-dependent signaling. A single injection of MPLA caused rapid mobilization and recruitment of neutrophils, a response that was largely mediated by the chemokines CXCL1 and -2 and the hemopoietic factor G-CSF. Rapid neutrophil recruitment and chemokine production were regulated by both pathways although the MyD88-dependent pathway showed some predominance. In further studies, multiple injections of MPLA potently induced mobilization and recruitment of neutrophils and monocytes. Neutrophil recruitment after multiple injections of MPLA was reliant on MyD88-dependent signaling, but effective monocyte recruitment required activation of both pathways. MPLA treatment induced expansion of myeloid progenitors in bone marrow and upregulation of CD11b and shedding of L-selectin by neutrophils, all of which were attenuated in MyD88- and TRIF-deficient mice. These results show that MPLA-induced neutrophil and monocyte recruitment, expansion of bone marrow progenitors and augmentation of neutrophil adhesion molecule expression are regulated by both the MyD88- and TRIF-dependent pathways.

Mast cells and histamine play an important role in edema and leukocyte recruitment induced by Potamotrygon motoro stingray venom in mice

This work aimed to investigate mechanisms underlying the inflammatory response caused by Potamotrygon motoro stingray venom (PmV) in mouse paws. Pre-treatment of animals with a mast cell degranulation inhibitor (cromolyn) diminished edema (62% of inhibition) and leukocyte influx into the site of PmV injection. Promethazine (histamine type 1 receptor antagonist) or thioperamide (histamine type 3 and 4 receptor antagonist) also decreased edema (up to 30%) and leukocyte numbers, mainly neutrophils (40-50 %). Cimetidine (histamine type 2 receptor antagonist) had no effect on PmV-induced inflammation. In the RBL-2H3 lineage of mast cells, PmV caused proper cell activation, in a dose-dependent manner, with release of PGD2 and PGE2. In addition, the role of COXs products on PmV inflammatory response was evaluated. Indomethacin (COX-1/COX-2 inhibitor) or etoricoxib (COX-2 inhibitor) partially diminished edema (around 20%) in PmV-injected mice. Indomethacin, but not etoricoxib, modulated neutrophil influx into the site of venom injection. In conclusion, mast cell degranulation and histamine, besides COXs products, play an important role in PmV-induced reaction. Since PmV mechanism of action remains unknown, hindering accurate treatment, clinical studies can be performed to validate the prescription of antihistaminic drugs, besides NSAIDs, to patients injured by freshwater stingrays.

NSAIDs: learning new tricks from old drugs

Nonsteroidal anti-inflammatory drugs (NSAIDs) comprise a heterogeneous group of pharmacological agents used for the symptomatic treatment of fever, pain, and inflammation. Although the main mechanism of action of NSAIDs consists of inhibiting prostaglandin synthesis by blocking the enzyme cyclooxygenase (COX), clinical, and experimental data strongly indicate the existence of additional mechanisms. Some of the COX-independent effects are related to the ability of NSAIDs to penetrate biological membranes and disrupt important molecular interactions necessary for a wide array of cellular functions, including cell adhesion. These effects, in particular those that interfere with L-selectin function in neutrophils during the inflammatory response, may contribute to the anti-inflammatory properties that NSAIDs exert in vivo. Recent contributions in this field have shown that the anti-L-selectin effect of NSAIDs is related to the NADPH-oxidase-dependent generation of superoxide anion at the plasma membrane. These findings might represent a novel approach for developing new and effective anti-inflammatory compounds with a better safety profile than the currently available NSAIDs.

Exogenous application of hydrogen sulfide donor attenuates inflammatory reactions through the L-selectin-involved pathway in the cutaneous reverse passive Arthus reaction

H2S has been highlighted recently as an endogenous, gaseous signaling molecule, especially in inflammations. The deposition of IC induces an acute inflammatory response with tissue injury. To assess the roles of H2S in the IC-induced diseases, the cutaneous, reverse passive Arthus reaction was conducted using NaHS as a H2S donor. Furthermore, we conducted similar experiments using selectin(-/-) mice to determine the involvement of selectin molecules in the H2S-mediated pathway. Exogenous application of NaHS dramatically attenuated inflammatory reactions in WT mice associated with Arthus reaction. Namely, mRNA expressions of TNF-α, IFN-γ, and neutrophil numbers were reduced significantly in the lesional skins of NaHS-treated WT mice relative to untreated ones. NaHS treatment significantly reduced these three parameters in the lesional skins of E- and P-selectin(-/-) mice but not in those of L-selectin(-/-) mice. Quite similar results were obtained in the blocking study using WT mice injected with mAb to E-, P-, and L-selectin. Our results indicated that the exogenous application of NaHS attenuates inflammatory responses in reverse passive Arthus reaction through a L-selectin-involved pathway but not through E- or P-selectin pathways.

Isolated blunt chest injury leads to transient activation of circulating neutrophils

Introduction

The acute respiratory distress syndrome (ARDS) is a severe and frequently seen complication in multi-trauma patients. ARDS is caused by an excessive innate immune response with a clear role for neutrophils. As ARDS is more frequently seen in trauma patients with chest injury, we investigated the influence of chest injury on the systemic neutrophil response and the development of ARDS.

Materials and methods

Thirteen patients with isolated blunt chest injury [abbreviated injury score (AIS) 2–5] were included. To avoid systemic inflammation caused by tissue damage outside the thorax, injuries to other regions than the chest did not exceed an AIS of 2. At 3, 9 and 24 h after injury, the expression of circulating activating molecules on neutrophils and levels of circulating interleukine (IL)-6 were determined. Blood samples from eight healthy volunteers were used as control.

Results

Blunt chest injury resulted in the activation of circulating neutrophils, as characterized by a decreased expression of l-selectin (CD62L), CXCR2 (CD182b) and C5aR (CD88) compared to control (p < 0.05). Expression of l-selectin, CXCR2 and C5aR was partially restored at 24 h after injury. In addition, the mean expression of FcγRIII (CD16) dropped (p < 0.001), indicating the recruitment of young neutrophils into the circulation. IL-6 levels increased to a maximum mean concentration of 86 ± 31 pg/ml at 24 h postinjury. None of the patients developed ARDS.

Conclusion

Blunt chest trauma caused a systemic inflammatory reaction with transient activation of neutrophils and mobilization of young neutrophils into the circulation. Isolated chest injury, however, was not abundant enough to cause ARDS, so a second hit appears crucial.

Do non-steroidal anti-inflammatory drugs influence chronic inflammation? The effects of piroxicam on chronic antigen-induced arthritis in rats

OBJECTIVE

The effects of non-steroidal anti-inflammatory drugs (NSAIDs) on acute inflammation have been thoroughly investigated. NSAIDs are, however, also prescribed for patients with chronic inflammation, such as rheumatoid arthritis (RA), and objective improvement suggestive of anti-inflammatory action from NSAIDs has not been convincingly shown in chronic RA. An antigen-induced arthritis (AIA) model was used to investigate the effects of piroxicam on chronic inflammation.

METHODS

AIA was induced by injecting methylated bovine serum albumin (mBSA) into the knee joints of previously immunized rats that were treated orally with the NSAID piroxicam or with saline. This treatment was started either before AIA was induced or after it had reached a chronic phase. The findings were recorded by clinical and histological assessment of the joints.

RESULTS

The piroxicam group developed significantly less acute and subsequent chronic knee joint inflammation but this was only evident if the drug was administered prior to the intra-articular mBSA injections. Piroxicam treatment that was initiated during the chronic inflammation did not have any clinical effect, whereas short-term corticosteroid treatment abolished the chronic inflammation. Moreover, histological analysis of the chronic inflammation revealed significantly more inflammatory changes in the piroxicam group compared with the control group.

CONCLUSIONS

Piroxicam treatment had no beneficial effects on the chronic stable inflammation in this model and might even delay histological resolution. As the anti-inflammatory effect of piroxicam is restricted to acute inflammation, the use of NSAIDs during periods of chronic stable arthritis in humans, such as in RA, may need to be investigated.

DP-155, a lecithin derivative of indomethacin, is a novel nonsteroidal antiinflammatory drug for analgesia and Alzheimer's disease therapy

DP-155 is a lipid prodrug of indomethacin that comprises the latter conjugated to lecithin at position sn-2 via a 5-carbon length linker. It is cleaved by phospholipase A2 (PLA)(2) to a greater extent than similar compounds with linkers of 2, 3, and 4 carbons. Indomethacin is the principal metabolite of DP-155 in rat serum and, after DP-155 oral administration, the half-life of the metabolite was 22 and 93 h in serum and brain, respectively, compared to 10 and 24 h following indomethacin administration. The brain to serum ratio was 3.5 times higher for DP-155 than for indomethacin. In vitro studies demonstrated that DP-155 is a selective cyclooxygenase (COX)-2 inhibitor. After it is cleaved, its indomethacin derivative nonselectively inhibits both COX-1 and -2. DP-155 showed a better toxicity profile probably due to the sustained, low serum levels and reduced maximal concentration of its indomethacin metabolite. DP-155 did not produce gastric toxicity at the highest acute dose tested (0.28 mmol/kg), while indomethacin caused gastric ulcers at a dose 33-fold lower. Furthermore, after repeated oral dosing, gastrointestinal and renal toxicity was lower (10- and 5-fold, respectively) and delayed with DP-155 compared to indomethacin. In addition to reduced toxicity, DP-155 had similar ameliorative effects to indomethacin in antipyretic and analgesia models. Moreover, DP-155 and indomethacin were equally efficacious in reducing levels of amyloid ss (Ass)42 in transgenic Alzheimer's disease mouse (Tg2576) brains as well as reducing Ass42 intracellular uptake, neurodegeneration, and inflammation in an in vitro AD model. The relatively high brain levels of indomethacin after DP-155 administration explain the equal efficacy of DP-155 despite its low systemic blood concentrations. Compared to indomethacin, the favored safety profile and equal efficacy of DP-155 establish the compound as a potential candidate for chronic use to treat AD-related pathology and for analgesia.

Conformational activation of CD11b without shedding of L-selectin on circulating human neutrophils

Membrane-activated complex 1 (Mac-1; CD11b/CD18) is a beta(2) integrin implicated in the pathophysiology of neutrophil-mediated tissue injury whose functional capacity is determined by stimulus-induced conformational activation rather than up-regulation. Mac-1 up-regulation and conformational activation, together with shedding of L-selectin, are reported after in vitro neutrophil activation. However, their regulation on circulating human neutrophils during acute inflammation is unclear. Using flow cytometry, we investigated neutrophil expression of Mac-1, its activation-reporter neo-epitope CBRM1/5, and L-selectin during the inflammatory stimulus of cardiac surgery. A subpopulation of circulating neutrophils expressed CBRM1/5 (CBRM1/5+) under basal conditions (6.28+/-2.59%) and was persistently expanded (9.95+/-4.0%-15.2+/-4.2%; P<0.0001) peri-operatively, whereas total CD11b expression increased only transiently, intra-operatively. L-selectin expression was unchanged on CBRM1/5+ neutrophils, and soluble L-selectin levels decreased intra-operatively (P<0.01), indicating that L-selectin was not shed. Increased CBRM1/5 expression without L-selectin loss or CD11b up-regulation was replicated in vitro by neutrophil stimulation with IL-8, C3a, and platelet-activating factor. Heparin, a known CD11b ligand, which is administered during cardiac surgery, markedly reduced neutrophil expression of conformationally active CD11b in vivo and in vitro, identifying a potential mechanism for its anti-inflammatory properties. We conclude that conformational activation of CD11b occurs on circulating neutrophils in vivo and can occur in the absence of CD11b up-regulation and L-selectin shedding.

Nonsteroidal anti-inflammatory drug-induced fracture nonunion: an inhibition of angiogenesis?

BACKGROUND

Approximately 5% to 10% of fractures may result in delayed union or nonunion. The results of research done over the past three decades have shown that the use of nonsteroidal anti-inflammatory drugs (NSAIDs) has an inhibitory effect on fracture repair, but the exact mechanism of action remains to be elucidated. Cancer research has identified that NSAIDs impede cell proliferation by inhibiting angiogenesis. It is proposed that a similar mechanism occurs in the induction of NSAID-induced nonunions. This hypothesis was investigated in a randomized placebo-controlled trial of the NSAID rofecoxib with use of a murine femoral fracture model.

METHODS

Two hundred and forty mice were randomized to receive either the nonsteroidal anti-inflammatory drug rofecoxib (5 mg/kg orally) in a 0.5% methylcellulose solution (the NSAID group) or the 0.5% methylcellulose solution only (the control group). Two hundred and thirty-five of the 240 mice underwent surgery to induce an open transverse middiaphyseal femoral fracture, which was then treated with use of a custom-made external fixator. Five additional animals underwent sham surgery with no fracture induced. Outcomes measures included radiographic assessment, histologic analysis, biomechanical testing, and use of laser Doppler flowmetry to assess blood flow across the fracture gap.

RESULTS

Radiography revealed similar healing patterns in both groups; however, at the later stages (day 32), the NSAID group had poorer healing. Histological analysis demonstrated that the control animals healed quicker (at days 24 and 32) and had more callus and less fibrous tissue (at days 8 and 32) than the NSAID animals did. Biomechanical testing found that the control animals were stronger at day 32. Both groups exhibited a similar pattern of blood flow; however, the NSAID group exhibited a lower median flow from day 4 onward (significant at days 4, 16, and 24). Positive correlations were demonstrated between both histological and radiographic assessments of healing and increasing blood flow. NSAID-treated animals exhibited lower blood flow and poorer healing by all parameters. Regression analysis, however, demonstrated that the negative effect of NSAIDs on fracture repair is independent of its inhibitory action on blood flow.

CONCLUSIONS

Following the development of a novel method of analyzing functional vascularity across a fracture gap, we have demonstrated that the cyclooxygenase-2 (COX-2) inhibitor rofecoxib has a significant negative effect on blood flow across the fracture gap as well as an inhibiting effect on fracture repair.

CLINICAL RELEVANCE

COX-2 inhibitors are marketed as having low side-effect profiles. We propose that these drugs should be used with caution in all patients following osseous trauma and, in particular, after injuries that may already predispose a fracture to a delayed union due to osseous, vascular, or patient-related factors.

Comparative study of anti-inflammatory and ulcerogenic activities of different cyclo-oxygenase inhibitors

The aim of the present work was to study the in vivo anti-inflammatory activity of six NSAIDs, ibuprofen, diclofenac, nimesulide, meloxicam, celecoxib and rofecoxib, using the rat air-pouch model of inflammation to characterize the ability of these drugs to induce gastric damage and PGE(2) inhibition. Selective compounds were observed to have no ulcerogenic properties at anti-inflammatory doses; however, these drugs were weaker inhibitors of several inflammatory aspects such as cell influx and exudate formation. In contrast, the non-selective and preferential compounds present anti-inflammatory properties at lower doses than presented by selective drugs. At anti-inflammatory doses, only meloxicam and ibuprofen produced gastric damage and inhibition of PGE(2) synthesis, suggesting that ulcerogenic properties of NSAIDs cannot be predicted by their selectivity index, since meloxicam demonstrates ulcerogenic properties despite its preferential profile.

Pathophysiology of disk-related sciatica. I.--Evidence supporting a chemical component

Sciatica in patients with disk disease was long ascribed to pressure put on the sciatic nerve root by a herniated disk. However, a role for chemical factors acting in conjunction with this mechanical insult is suggested by a number of clinical observations: disk surgery does not consistently provide pain relief, large disk herniations are not always symptomatic, severe pain may be present in patients without imaging evidence of nerve root compression, the severity of symptoms and neurological signs is not well correlated with the size of the disk herniation, and conservative therapy is often effective. Experimental studies have provided further evidence for a chemical component: disk herniations can undergo spontaneous resorption, the intervertebral disk is immunogenic, and mediators for inflammation have been identified within intervertebral disk tissue. The current pathophysiological theory incriminates proinflammatory substances secreted by the nucleus pulposus (NP). When preexisting or concomitant mechanical injury to a nerve root occurs, these substances can cause nerve root pain. Animal experiments have established that the NP can induce functional and structural nerve root abnormalities in the absence of mechanical compression and that this effect is mediated by substances located at the surface of NP cells. Methylprednisolone, diclofenac, indomethacin, doxycycline, and cyclosporine induce variable inhibition of this effect. Available information points to tumor necrosis factor-alpha (TNF-alpha) as the main candidate among substances potentially responsible for nerve root pain. Therefore, trials of TNF-alpha antagonists in patients with disk-related sciatica are warranted.

Management of reactive arthritis

Reactive arthritis (ReA) is an aseptic form of articular inflammation induced by infections mainly localised in the gastrointestinal (enteroarthritis) or urogenital (uroarthritis) tracts. The bacteria principally involved as causative agents are Chlamydia, Salmonella, Shigella, Campylobacter and Yersinia. The clinical picture is usually characterised by a mono-oligoarthritis of the lower limbs. Axial involvement is possible and extra-articular manifestations such as enthesitis, tenosynovitis, bursitis and dactylitis are frequent. NSAIDs and sulfasalazine are still the drugs most commonly used in the treatment of ReA. Steroids are administered when inflammatory symptoms are resistant to NSAIDs. Experiences with other DMARDs (disease modifying antirheumatic drugs) such as azathioprine, methotrexate and cyclosporin, have been sporadically reported and they can be employed in patients that are unresponsive to the more usual medicaments. The intake of antibacterials (tetracyclines) may be useful in uroarthritis but have not been so successful in enteroarthrits. In more aggressive cases, or when ReA evolves towards ankylosing spondylitis, TNF-alpha blockers could represent an effective choice.

HLA-B27-associated reactive arthritis: pathogenetic and clinical considerations

Current evidence supports the concept that reactive arthritis (ReA) is an immune-mediated synovitis resulting from slow bacterial infections and showing intra-articular persistence of viable, non-culturable bacteria and/or immunogenetic bacterial antigens synthesized by metabolically active bacteria residing in the joint and/or elsewhere in the body. The mechanisms that lead to the development of ReA are complex and basically involve an interaction between an arthritogenic agent and a predisposed host. The way in which a host accommodates to invasive facultative intracellular bacteria is the key to the development of ReA. The details of the molecular pathways that explain the articular and extra-articular manifestations of the disease are still under investigation. Several studies have been done to gain a better understanding of the pathogenesis of ReA; these constitute the basis for a more rational therapeutic approach to this disease.

Cell adhesion molecules, leukocyte trafficking, and strategies to reduce leukocyte infiltration

Leukocyte-endothelial cell interactions are mediated by various cell adhesion molecules. These interactions are important for leukocyte extravasation and trafficking in all domestic animal species. An initial slowing of leukocytes on the vascular endothelium is mediated by selectins. This event is followed by (1) activation of beta2 integrins after leukocyte exposure to cytokines and pro-inflammatory mediators, (2) adherence of leukocyte beta2 integrins to vascular endothelial ligands (eg, intercellular adhesion molecule-1 [ICAM-1]), (3) extravasation of leukocytes into tissues through tight junctions of endothelial cells mediated by platelet and endothelial cell adhesion molecule-1 (PECAM-1), and (4) perivascular migration through the extracellular matrix via beta1 integrins. Inhibiting excessive leukocyte egress and subsequent free radical-mediated damage caused by leukocyte components may attenuate or eliminate tissue damage. Several methods have been used to modify leukocyte infiltration in various animal models. These methods include nonspecific inhibition of pro-inflammatory mediators and adhesion molecules by nonsteroidal anti-inflammatory drugs (NSAIDs) and glucocorticoids, inhibition of cytokines and cytokine receptors, and inhibition of specific types of cell adhesion molecules, with inhibitors such as peptides and antibodies to beta2 integrins, and inhibitors of selectins, ICAMs, and vascular cell adhesion molecule-1 (VCAM-1). By understanding the cellular and molecular events in leukocyte-endothelial cell interactions, therapeutic strategies are being developed in several animal models and diseases in domestic animal species. Such therapies may have clinical benefit in the future to overcome tissue damage induced by excessive leukocyte infiltration.

Inhibition of LFA-1/ICAM-1 and VLA-4/VCAM-1 as a therapeutic approach to inflammation and autoimmune diseases

This review focuses on providing insights into the structural basis and clinical relevance of LFA-1 and VLA-4 inhibition by peptides and small molecules as adhesion-based therapeutic strategies for inflammation and autoimmune diseases. Interactions of cell adhesion molecules (CAM) play central roles in mediating immune and inflammatory responses. Leukocyte function-associated antigen (LFA-1, alpha(L)beta(2), and CD11a/CD18) and very late antigen (VLA-4, alpha(4)beta(1), and CD49d/CD29) are members of integrin-type CAM that are predominantly involved in leukocyte trafficking and extravasation. LFA-1 is exclusively expressed on leukocytes and interacts with its ligands ICAM-1, -2, and -3 to promote a variety of homotypic and heterotypic cell adhesion events required for normal and pathologic functions of the immune systems. VLA-4 is expressed mainly on lymphocyte, monocytes, and eosinophils, but is not found on neutrophils. VLA-4 interacts with its ligands VCAM-1 and fibronectin (FN) CS1 during chronic inflammatory diseases, such as rheumatoid arthritis, asthma, psoriasis, transplant-rejection, and allergy. Blockade of LFA-1 and VLA-4 interactions with their ligands is a potential target for immunosuppression. LFA-1 and VLA-4 antagonists (antibodies, peptides, and small molecules) are being developed for controlling inflammation and autoimmune diseases. The therapeutic intervention of mostly mAb-based has been extensively studied. However, due to the challenging relative efficacy/safety ratio of mAb-based therapy application, especially in terms of systemic administration and immunogenic potential, strategic alternatives in the forms of peptide, peptide mimetic inhibitors, and small molecule non-peptide antagonists are being sought. Linear and cyclic peptides derived from the sequences of LFA-1, ICAM-1, ICAM-2, VCAM-1, and FN C1 have been shown to have inhibitory effects in vitro and in vivo. Finally, understanding the mechanism of LFA-1 and VLA-4 binding to their ligands has become a fundamental basis in developing therapeutic agents for inflammation and autoimmune diseases.

Gelatinase B: a tuner and amplifier of immune functions

Gelatinase B (matrix metalloproteinase-9) is a secreted multidomain enzyme that is important for the remodeling of the extracellular matrix and the migration of normal and tumor cells. It cleaves denatured collagens (gelatins) and type IV collagen, which is present in basement membranes. In the immune system, this cleavage helps lymphocytes and other leukocytes to enter and leave the blood and lymph circulations. Gelatinase B also cleaves myelin basic protein and type II gelatins, and this clipping leads to remnant epitopes that generate autoimmunity, the so-called REGA model of autoimmunity. Recently, gelatinase B has been found to process cytokines and chemokines, resulting in skewed immune functions. Therefore, gelatinase B, often considered as a pure effector molecule, acts as a switch and catalyst in both innate and specific immunity, and constitutes a prototypic example of the regulation of immune functions by proteolysis.

NSAIDs inhibit alpha V beta 3 integrin-mediated and Cdc42/Rac-dependent endothelial-cell spreading, migration and angiogenesis

Cyclooxygenase-2 (COX-2), a key enzyme in arachidonic acid metabolism, is overexpressed in many cancers. Inhibition of COX-2 by nonsteroidal anti-inflammatory drugs (NSAIDs) reduces the risk of cancer development in humans and suppresses tumor growth in animal models. The anti-cancer effect of NSAIDs seems to involve suppression of tumor angiogenesis, but the underlying mechanism is not completely understood. Integrin alpha V beta 3 is an adhesion receptor critically involved in mediating tumor angiogenesis. Here we show that inhibition of endothelial-cell COX-2 by NSAIDs suppresses alpha V beta 3-dependent activation of the small GTPases Cdc42 and Rac, resulting in inhibition of endothelial-cell spreading and migration in vitro and suppression of fibroblast growth factor-2-induced angiogenesis in vivo. These results establish a novel functional link between COX-2, integrin alpha V beta 3 and Cdc42-/Rac-dependent endothelial-cell migration. Moreover, they provide a rationale to the understanding of the anti-angiogenic activity of NSAIDs.

Bacteria-Triggered reactive arthritis: implications for antibacterial treatment

Reactive arthritis (ReA) is definitely caused by an infection. Several observations suggest that the triggering microbe may persist in the tissues of the patient for a prolonged time. The obvious conclusion is to consider antibacterial treatment. In two instances antibacterial agents are of definite value: in the primary and secondary prevention of rheumatic fever and for early eradication of Borrelia burgdorferi in order to prevent development of the arthritis associated with Lyme disease. Altogether, clinical and experimental data exist to indicate that if antibacterial treatment of ReA can be started very early during the pathogenetic process, the disease can be prevented or the prognosis improved. In fully developed ReA, the value of antibacterial agents is less certain. All available evidence indicates that short term antibacterial treatment has no effect on the prognosis and final outcome of ReA, and the results with long term administration of antibacterials are also overall poor. In some instances sulfasalazine appears useful, rather as a result of its antirheumatic effect or influence on an underlying inflammatory bowel disease than its action as an antibacterial agent. Tetracyclines have also been found to have an effect on ReA, but again, this is probably due to their anti-inflammatory action rather than any antibacterial effect.

Effects of food intake and oxidative stress on intestinal lesions caused by meloxicam and piroxicam in rats

Large intestinal ulcers, bleeding and perforation are occasionally due to non-steroidal anti-inflammatory drugs (NSAID). In addition to suppression of prostaglandins synthesis, a number of factors have been implicated, including enterohepatic recirculation, food intake and vascular injury with oxygen free-radical generation. The present study aimed to determine the effect of food intake and the role of oxidative stress in the pathogenesis of intestinal injury induced by oral administration of meloxicam (preferential cyclooxygenase-2 inhibitor) vs. piroxicam (preferential cyclooxygenase-1 inhibitor). Therefore, the activity of oxidative stress-related enzymes such as myeloperoxidase, xanthine oxidase and superoxide dismutase, as well as levels of lipid peroxides and glutathione homeostasis were studied in an experimental model using re-fed rats. The animals treated with piroxicam (10-20 mg/kg) had a dose-dependent increase in the severity of intestinal lesions, but only the highest dose of meloxicam (15 mg/kg) caused macroscopic damage. The severity of piroxicam and meloxicam-induced damage was correlated with a significant increase of xantine oxidase activity and a decrease of superoxide dismutase activity and glutathione levels (P<0.05 and P<0.001 vs. control). In contrast, there was no significant neutrophil infiltration of the intestine after dosing. Our results support the hypothesis that oxygen free radicals, probably derived via the action of xantine oxidase, the decrease in superoxide dismutase activity, and depletion of mucosal glutathione contribute to the pathogenesis of meloxicam and piroxicam-induced intestinal ulceration in re-fed rats.

Drugs, inflammation and cell adhesion receptors

The cell adhesion receptors that participate in the extravasation and migration of leucocytes towards inflammatory foci mainly include the selectins and different members of the integrin and immunoglobulin superfamilies. These adhesion receptors mediate the sequential steps of leucocyte-endothelial cell interaction and, together with chemoattractant molecules (e.g., chemokines), direct the influx of inflammatory cells and define the characteristics of the cell infiltrate. Many different drugs, including non-steroidal anti-inflammatory drugs (NSAIDs), glucocorticoids, rheumatoid arthritis disease-modifying agents and phosphodiesterase inhibitors, interfere with the expression and/or function of cell adhesion receptors and this effect accounts for, at least in part, their anti-inflammatory activity. In recent years, novel approaches for the modulation of the cell membrane receptors involved in inflammation have been active areas in pharmaceutical research. Upgraded synthetic blocking compounds, chimeric monoclonal antibodies or improved antisense oligonucleotides represent important advances in this field. The proper development of these novel approaches, as well as other alternative strategies, will allow a better and more specific pharmacological modulation of the inflammatory phenomenon.

COX-2 inhibitors vs. NSAIDs in gastrointestinal damage and prevention

Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit production of protective gastric mucosal prostaglandins and also have a direct topical irritant effect. In some patients this results in dyspepsia and development of gastroduodenal erosions and ulceration. The risk of ulcer complications, such as bleeding, perforation and death is increased approximately 4-fold in NSAID users. Patients at high risk of ulcer complications include the elderly, those taking anticoagulants, steroids and aspirin, those with a previous history of peptic ulceration and patients with concomitant serious medical problems. The interaction of NSAIDs with Helicobacter pylori (the major cause of peptic ulceration in non-NSAID users) is controversial and some studies suggest that H. pylori infection may even protect against NSAID-induced ulceration. Selective inhibitors of the inducible cyclooxygenase-2 (COX-2) enzyme spare COX-1 in the gastric mucosa and, hence, do not inhibit production of mucosal prostaglandins. COX-2-selective inhibitors are associated with a significant reduction in gastroduodenal damage compared with traditional NSAIDs. Proton pump inhibitors (PPI) are probably the best agents for healing and prevention of NSAID-induced ulcers. Preliminary studies suggest that COX-2 selective inhibitors, like traditional NSAIDs, may prevent lower gastrointestinal cancer. Further studies are needed but they may be useful in individuals at high risk of certain types of lower gastrointestinal malignancy with increased gastrointestinal tolerability and safety.

Down-regulation of L-selectin expression in neutrophils by nonsteroidal anti-inflammatory drugs: role of intracellular ATP concentration

L-selectin is an adhesion molecule that plays an essential role in the early events of the inflammatory response. Our group has recently described that several nonsteroidal anti-inflammatory drugs (NSAIDs) are able to induce both in vivo and in vitro the shedding of L-selectin in neutrophils through an unknown mechanism. In this work, we have studied potential mechanisms involved in the shedding of L-selectin induced by NSAIDs. This effect of NSAIDs did not involve any detectable intracellular calcium flux. Pretreatment of neutrophils either with Ro 31-8220 and H7, 2 specific inhibitors of protein kinase C (PKC), or with inhibitors of protein tyrosine kinases such as tyrphostin A25 or herbimycin A did not prevent the NSAID-mediated L-selectin shedding. However, the KD-IX-73-4, an inhibitor of L-selectin proteolysis was able to block the effect of NSAIDs on L-selectin expression. Remarkably, NSAIDs caused a variable reduction in the neutrophil intracellular ATP concentration that highly correlated with the differential ability of NSAIDs to trigger L-selectin shedding (r = 0.8, P &lt; .01). In agreement with this finding, azide plus 2-deoxy-D-glucose, 2 metabolic blockers, also induced a rapid L-selectin shedding (65% ± 8%) without affecting the neutrophil viability, activation, or expression level of other surface molecules with soluble isoforms such as CD16 and CD59. These data indicate that the maintenance of L-selectin on the neutrophil surface requires energy consumption, which suggests that L-selectin is shed in neutrophils by default. Interestingly, NSAIDs seem to cause the shedding of L-selectin, at least in part, through the reduction of the intracellular ATP concentration.

Down-regulation of L-selectin expression in neutrophils by nonsteroidal anti-inflammatory drugs: role of intracellular ATP concentration

L-selectin is an adhesion molecule that plays an essential role in the early events of the inflammatory response. Our group has recently described that several nonsteroidal anti-inflammatory drugs (NSAIDs) are able to induce both in vivo and in vitro the shedding of L-selectin in neutrophils through an unknown mechanism. In this work, we have studied potential mechanisms involved in the shedding of L-selectin induced by NSAIDs. This effect of NSAIDs did not involve any detectable intracellular calcium flux. Pretreatment of neutrophils either with Ro 31-8220 and H7, 2 specific inhibitors of protein kinase C (PKC), or with inhibitors of protein tyrosine kinases such as tyrphostin A25 or herbimycin A did not prevent the NSAID-mediated L-selectin shedding. However, the KD-IX-73-4, an inhibitor of L-selectin proteolysis was able to block the effect of NSAIDs on L-selectin expression. Remarkably, NSAIDs caused a variable reduction in the neutrophil intracellular ATP concentration that highly correlated with the differential ability of NSAIDs to trigger L-selectin shedding (r = 0.8, P < .01). In agreement with this finding, azide plus 2-deoxy-D-glucose, 2 metabolic blockers, also induced a rapid L-selectin shedding (65% ± 8%) without affecting the neutrophil viability, activation, or expression level of other surface molecules with soluble isoforms such as CD16 and CD59. These data indicate that the maintenance of L-selectin on the neutrophil surface requires energy consumption, which suggests that L-selectin is shed in neutrophils by default. Interestingly, NSAIDs seem to cause the shedding of L-selectin, at least in part, through the reduction of the intracellular ATP concentration.

Mechanisms of NSAID-induced gastrointestinal injury defined using mutant mice

BACKGROUND & AIMS

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used agents that have a high incidence of gastrointestinal side effects resulting in significant morbidity and mortality. Leukocytes have been implicated in NSAID-induced injury, but the mechanisms are unclear. We established a murine model of NSAID-induced gastrointestinal damage to assess the roles of candidate gene products in the pathogenesis of this injury.

METHODS

Indomethacin-induced gastrointestinal injury was assessed in wild-type and several mutant murine lines. Leukocyte involvement was assessed by neutrophil depletion, impairment of recruitment (resulting from targeted disruption of fucosyltransferase VII [FTVII]), and the absence of mature T and B cells with the use of Rag 2(-/-) mice. Activation and oxygen free radicals were assessed using gp91(phox-/-) mice that exhibit normal leukocyte recruitment but are deficient in myeloid cell activation and oxygen free radical generation.

RESULTS

Impairment of leukocyte recruitment (FTVII(/-)) and neutrophil depletion resulted in more than a 50% reduction in NSAID-induced injury. However, mice deficient in mature T and B cells had NSAID-induced damage comparable to control mice. Leukocyte activation was required for NSAID-induced damage because the gp91(phox-/-) mice were less susceptible to NSAID injury than wild-type mice.

CONCLUSIONS

In this murine model system, FTVII-dependent leukocyte recruitment, leukocyte activation via gp91(phox), and neutrophils are required for NSAID-induced gastrointestinal injury, whereas T and B cells are not essential.

Chlamydia and associated arthritis

An inflammatory arthritis is known to follow urogenital infection with the intracellular bacterium Chlamydia trachomatis in some individuals, and recent research results have elucidated important aspects of the characteristics of this Chlamydia-associated joint disease. Although the several extra-articular features of Chlamydia-induced arthritis have been defined clinically, their detailed causes remain largely unexplained. Current data indicate that the clinical characteristics of joint disease associated with C. trachomatis infection and those associated with postenteric arthritis are not easily distinguishable, although the response of each to antibiotic therapy does differ. The biologic characteristics of Chlamydia and enteric organisms in the joint show profound differences, and these are probably responsible for the variable responses to drug treatment. Molecular analyses of synovial C. trachomatis have demonstrated that long-term infection of the joint occurs primarily in synovial tissue and that the organism exhibits highly unusual biologic properties in its synovial context. These unusual molecular, biochemical, and other characteristics provide explanations for the frequent culture negativity of joint materials for C. trachomatis and for several other aspects of the arthritogenic process. Much remains to be learned concerning the behavior of this organism in the joint and concerning its interaction with its synovial host cells.

Anti-Inflammatory Actions of Lipoxin A4 Stable Analogs Are Demonstrable in Human Whole Blood: Modulation of Leukocyte Adhesion Molecules and Inhibition of Neutrophil-Endothelial Interactions

We have examined in whole blood the actions of 2 lipoxin A4 (LXA4) stable analogs, 15-R/S-methyl-LXA4 and 16-phenoxy-LXA4, for their impact on the expression of adhesion molecules on human leukocytes and coronary artery endothelial cells (HCAEC) and on neutrophil adhesion to HCAEC in vitro. Both LXA4 analogs in nanomolar to micromolar concentrations prevented shedding of L-selectin and downregulated CD11/CD18 expression on resting neutrophils, monocytes, and lymphocytes. Changes in CD11/CD18 expression were blocked by the mitogen-activated protein kinase kinase inhibitor PD98059. The LXA4 analogs also attenuated changes in L-selectin and CD11/CD18 expression evoked by platelet-activating factor (PAF), interleukin-8, or C-reactive protein-derived peptide 201-206 with IC50 values of 0.2 to 1.9 μmol/L, whereas they did not affect lipopolysaccharide (LPS)– or tumor necrosis factor-–stimulated expression of E-selectin and intercellular adhesion molecule-1 on HCAEC. These LXA4analogs markedly diminished adhesion of neutrophils to LPS-activated HCAEC. Inhibition of adhesion was additive with function blocking anti–E-selectin and anti–L-selectin antibodies, but was not additive with anti-CD18 antibody. Combining LXA4 analogs with dexamethasone (100 nmol/L) almost completely inhibited PAF-induced changes in adhesion molecule expression on leukocytes and gave additive inhibition of neutrophil adhesion to HCAEC. Culture of HCAEC with dexamethasone, but not with LXA4 analogs, also decreased neutrophil attachment. Together, these results indicate that LXA4 stable analogs modulate expression of both L-selectin and CD11/CD18 on resting and immunostimulated leukocytes and inhibit neutrophil adhesion to HCAEC by attenuating CD11/CD18 expression. These actions are additive with those of glucocorticoids and may represent a novel and potent regulatory mechanism by which LXA4 and aspirin-triggered 15-epi-LXA4 modulate leukocyte trafficking.

Anti-Inflammatory Actions of Lipoxin A4 Stable Analogs Are Demonstrable in Human Whole Blood: Modulation of Leukocyte Adhesion Molecules and Inhibition of Neutrophil-Endothelial Interactions

We have examined in whole blood the actions of 2 lipoxin A4 (LXA4) stable analogs, 15-R/S-methyl-LXA4 and 16-phenoxy-LXA4, for their impact on the expression of adhesion molecules on human leukocytes and coronary artery endothelial cells (HCAEC) and on neutrophil adhesion to HCAEC in vitro. Both LXA4 analogs in nanomolar to micromolar concentrations prevented shedding of L-selectin and downregulated CD11/CD18 expression on resting neutrophils, monocytes, and lymphocytes. Changes in CD11/CD18 expression were blocked by the mitogen-activated protein kinase kinase inhibitor PD98059. The LXA4 analogs also attenuated changes in L-selectin and CD11/CD18 expression evoked by platelet-activating factor (PAF), interleukin-8, or C-reactive protein-derived peptide 201-206 with IC50 values of 0.2 to 1.9 μmol/L, whereas they did not affect lipopolysaccharide (LPS)– or tumor necrosis factor-–stimulated expression of E-selectin and intercellular adhesion molecule-1 on HCAEC. These LXA4analogs markedly diminished adhesion of neutrophils to LPS-activated HCAEC. Inhibition of adhesion was additive with function blocking anti–E-selectin and anti–L-selectin antibodies, but was not additive with anti-CD18 antibody. Combining LXA4 analogs with dexamethasone (100 nmol/L) almost completely inhibited PAF-induced changes in adhesion molecule expression on leukocytes and gave additive inhibition of neutrophil adhesion to HCAEC. Culture of HCAEC with dexamethasone, but not with LXA4 analogs, also decreased neutrophil attachment. Together, these results indicate that LXA4 stable analogs modulate expression of both L-selectin and CD11/CD18 on resting and immunostimulated leukocytes and inhibit neutrophil adhesion to HCAEC by attenuating CD11/CD18 expression. These actions are additive with those of glucocorticoids and may represent a novel and potent regulatory mechanism by which LXA4 and aspirin-triggered 15-epi-LXA4 modulate leukocyte trafficking.

Modulation of oxidant status by meloxicam in experimentally induced arthritis

Meloxicam is a new non-steroidal anti-inflammatory drug, that possesses a selective inhibition of the inducible isoform of cyclooxygenase enzyme (COX-2) relative to the constitutive one, COX-1. Oxidative stress has been documented to be involved in the aetiology of many pathological conditions. The present study aims to further explore the relationship between free radical generation and the inflammatory process, and extends more to investigate the effect of meloxicam on the oxidant status in experimentally induced arthritis, namely, Freund's adjuvant-induced arthritis in rats. Results of the present investigation revealed that animals inoculated with Freund's complete adjuvant showed a biphasic response regarding changes in the right hind paw oedema volume. During the chronic phase of the disease, arthritic animals showed an elevated plasma level of lipid peroxides, enhanced blood glutathione peroxidase activity, with depletion of plasma total thiols and albumin; while no significant effects have been observed on erythrocytic superoxide dismutase activity and plasma total proteins content, as compared to normal untreated rats. Long-term administration of meloxicam, at two dose levels, produced significant antioedemetous effect and succeeded in modulating the altered parameters affected during arthritis. The selected dose regimens of meloxicam did not show any apparent lesions in the gastric mucosa. The results of the present investigation lend further support to the reported observations concerning selective COX-2 inhibitors. The modulatory influence of meloxicam on the oxidant status, particularly on lipid peroxidation and thiols might be a relevant effect accounting for its anti-inflammatory properties.

No benefit of long-term ciprofloxacin treatment in patients with reactive arthritis and undifferentiated oligoarthritis: a three-month, multicenter, double-blind, randomized, placebo-controlled study

OBJECTIVE

To investigate the effect of long-term antibiotic treatment in patients with reactive arthritis (ReA) and undifferentiated oligoarthritis.

METHODS

One hundred twenty-six patients were treated with ciprofloxacin (500 mg twice a day) or placebo for 3 months, in a double-blind, randomized study. Of these patients, 104 (48 treated with ciprofloxacin and 56 treated with placebo) were valid for clinical evaluation: 55 were diagnosed as having ReA with a preceding symptomatic urogenic or enteric infection and 49 as having undifferentiated oligoarthritis. These 2 groups were randomized separately. The triggering bacterium was sought by serology and/or culture. The percentage of patients in remission after 3 months of treatment was chosen as the primary efficacy parameter.

RESULTS

A triggering bacterium could be identified in 52 patients (50%): Chlamydia trachomatis in 13, Yersinia in 14, and Salmonella in 25. No patient was positive for Campylobacter jejuni or for Shigella. No difference in outcome was found between treatment with ciprofloxacin or placebo in the whole group or in subgroups of patients with ReA or undifferentiated oligoarthritis. No difference was seen in patients with a disease duration <3 months. Ciprofloxacin was not effective in Yersinia- or Salmonella-induced arthritis but seemed to be better than placebo in Chlamydia-induced arthritis. This difference was not significant, however, which might be due to the small sample size.

CONCLUSION

Long-term treatment of ReA with ciprofloxacin is not effective; however, it might be useful in the subgroup of patients who have Chlamydia-induced arthritis. This has to be proven in a bigger study focusing on patients with Chlamydia-induced arthritis.

Non-steroidal anti-inflammatory drugs inhibit the expression of cytokines and induce HSP70 in human monocytes

Recent studies have shown that the non-steroidal anti-inflammatory drugs (NSAIDs) activate heat shock transcription factor (HSF1) from a latent cytoplasmic form to a nuclear, DNA binding state. As HSF1 can function as both an activator of heat shock genes and a repressor of non-heat shock genes such as IL1B and c- fos, we have examined the potential role of HSF1 in the effects of NSAIDs on gene expression in a human monocytic cell line THP-1. We found that two members of the NSAIDs, sodium salicylate and sulindac repress the IL1B promoter to similar degree to heat shock or HSF1 overexpression. In addition, sodium salicylate and additional NSAIDs used at concentrations that activate HSF1 also inhibited the expression of other monocytic genes (TNF-alpha, IL-1beta, IL-6, IL-8, IL-10, ICAM-1) activated by exposure to a pro-inflammatory stimulus (lipopolysaccharide, LPS). At least in the case of the IL1B promoter, repression did not seem to involve another factor whose activity is affected by the NSAIDs, NFkappaB as the IL1B promoter fragment used in our studies is not NFkappaB responsive and binds specifically to HSF1. Exposure to NSAIDs had a complex effect on HSP gene expression and while sulindac activated the stress responsive HSP70B promoter, sodium salicylate did not. In addition, only a subset of the NSAIDs induced HSP70 mRNA species. These findings reflect the properties of HSF1 which can be activated to at least two DNA binding forms only one of which activates heat shock promoters and suggest that individual NSAID family members may differentially induce one or other of these forms. Overall therefore, exposure to NSAIDs leads to a profound switch in gene expression in monocytic cells, with suppression of genes involved in macrophage activation and induction of stress genes and HSF1 appears to play a regulatory role in these effects.

Prevention of alphaII(b)beta3 activation by non-steroidal antiinflammatory drugs

We have studied the effect of non-steroidal antiinflammatory drugs (NSAIDs) on alphaII(b)beta3 integrin activation and platelet aggregation. NSAIDs such as meloxicam, piroxicam, indomethacin and aspirin, but not aceclofenac or diclofenac interfered with the activation state of alphaII(b)beta3. NSAIDs that inhibited alphaII(b)beta3 activation were also able both to partially inhibit platelet primary aggregation and to accelerate platelet deaggregation. These effects of NSAIDs were not dependent on cyclooxygenase inhibition. The results obtained indicate that some NSAIDs exert a specific action on alphaII(b)beta3 activation, and provide an additional mechanism that accounts for their beneficial effects in diseases in which platelet activation is involved.

The effects of intraperitoneal piroxicam and low molecular weight heparin in prevention of adhesion reformation in rat uterine horn

Our objective was to determine the effectiveness of intraperitoneal single dose piroxicam and low molecular weight heparin (LMWH) on prevention of adhesion reformation in the rat uterine horn. This study was carried out in the Surgical Research Laboratory, at Erciyes University. A standard lesion was created by unipolar electrocautery in 72 uterine horns of 36 female Wistar-Albino rats. After 2 weeks, adhesion formation scores were determined and adhesiolysis was performed in the second-look laparotomy. Animals were then randomly assigned into three groups. Each group contained 12 animals: group 1 was the control group where no adjuvant was given; in group 2, 1 ml 50 U Axa IC/ml solution LMWH was applied to the horns postoperatively, and in group 3, 1 ml 2 mg/ml piroxicam solution was applied to the horns after adhesiolysis. Two weeks later the rats were killed and adhesion reformation was evaluated. The number of horns with adhesion formation and the cumulative scores were not significantly different among the three groups in the second-look laparotomies, but after third-look laparotomies, the number of horns with adhesion reformation, after calculating the extent, severity and total scores of adhesion reformation, was found to be significantly less in LMWH and piroxicam groups than in the control group. Also, the effectiveness of piroxicam was significantly greater in all scores of adhesion reformation than LMWH was. In conclusion, both LMWH and piroxicam doses reduce adhesion reformation in the rat uterine horn, but the effectiveness of piroxicam is significantly greater than that of LMWH.

Tumor necrosis factor alpha and nucleus-pulposus-induced nerve root injury

STUDY DESIGN

The effects of nucleus pulposus and various treatments to block tumor necrosis factor alpha activity were evaluated in an experimental set-up using immunohistochemistry and nerve conduction velocity recordings.

OBJECTIVES

To assess the presence of tumor necrosis factor alpha in pig nucleus pulposus cells, and to see if block of tumor necrosis factor alpha also blocks the nucleus-pulposus-induced reduction of nerve root conduction velocity.

SUMMARY AND BACKGROUND DATA

A meta-analysis of observed effects induced by nucleus pulposus revealed that these effects might relate to one specific cytokine-tumor necrosis factor alpha.

METHODS

Series-1: Cultured nucleus pulposus cells were stained immunohistologically with a monoclonal antibody for tumor necrosis factor alpha. Series-2: Nucleus pulposus was harvested from lumbar discs and applied to the sacrococcygeal cauda equina in 13 pigs autologously. Four pigs received 100 mg of doxycycline intravenously; five pigs had a blocking monoclonal antibody to tumor necrosis factor alpha applied locally in the nucleus pulposus, and four pigs remained nontreated, forming a control group. Three days after the application, the nerve root conduction velocity was determined over the application zone by local electrical stimulation.

RESULTS

Series-1: Tumor necrosis factor alpha was found to be present in the nucleus pulposus cells. Series-2: The selective antibody to tumor necrosis factor alpha limited the reduction of nerve conduction velocity, although in comparison with the control group this was not statistically significant. However, treatment with doxycycline significantly blocked the nucleus-pulposus-induced reduction of conduction velocity.

CONCLUSION

For the first time, a specific substance, tumor necrosis factor alpha, has been linked to the nucleus-pulposus-induced effects of nerve roots after local application. Although the effects of this substance may be synergistic with those of other similar substances, the data of the current study may be of significant importance for the continued understanding of nucleus pulposus' biologic activity, and of possible potential use for future strategies in managing sciatica.

Adhesion molecules in inflammatory diseases

Cell adhesion molecules (CAM) have a key role in the inflammatory response. Selectins, integrins and immunoglobulin (Ig) gene superfamily adhesion receptors mediate the different steps of the migration of leucocytes from the blood-stream towards inflammatory foci. The activation of endothelial cells (EC) upregulates the expression of several CAM and triggers the interaction of these cells with leucocytes. Selectins are involved in the initial interactions (tethering/rolling) of leucocytes with activated endothelium, whereas integrins and Ig superfamily CAM mediate the firm adhesion of these cells and their subsequent extravasation. During rolling, leucocytes are activated through the intracellular signals generated by CAM and chemokine receptors. Blockade of the function or expression of CAM has emerged as a new therapeutic target in inflammatory diseases. Different drugs are able to interfere with cell adhesion phenomena. In addition, new antiadhesion therapeutic approaches (blocking monoclonal antibodies, soluble receptors, synthetic peptides, peptidomimetics, etc.) are currently in development.

Interference of nonsteroidal antiinflammatory drugs with very late activation antigen 4/vascular cells adhesion molecule 1-mediated lymphocyte-endothelial cell adhesion

OBJECTIVE

To study the effect of nonsteroidal antiinflammatory drugs (NSAIDs) on the adhesion of peripheral blood lymphocytes (PBL) to activated human umbilical vein endothelial cells (HUVEC) under conditions that resemble blood flow.

METHODS

Assays of adhesion of PBL to HUVEC or recombinant vascular cell adhesion molecule 1 (rVCAM-1), intercellular adhesion molecule 1 (ICAM-1), and E-selectin were performed under continuous rotation at 37 degrees C. The phenotype of PBL subpopulations attached was characterized by flow cytometry. Lymphocytes were pretreated with different doses (5-100 microg/ml) of aceclofenac, diclofenac, indomethacin, or piroxicam or with inhibitory monoclonal antibodies (MAb) prior to the adhesion assays. The effect of NSAIDs on lymphocyte adhesion molecules was assessed by flow cytometry. To determine whether NSAIDs interfere with the affinity state of very late activation antigen 4 (VLA-4) integrin, we studied the effect of these drugs on the appearance of a beta1 activation-dependent epitope recognized by the HUTS21 MAb both on human T lymphoblasts and on synovial fluid lymphocytes (SFL).

RESULTS

In the flow-resembling model, PBL-HUVEC adhesion was mainly mediated by the VLA-4/ VCAM-1 adhesion pathway. The major PBL subset attached was the CD3+, CD45RO+ memory T cell, with CD49d(high) expression. Aceclofenac, diclofenac, and indomethacin, but not piroxicam, were able to inhibit PBL adhesion to HUVEC or rVCAM-1. However, the quantitative expression of VLA-4 was not affected by treatment of PBL with any of the NSAIDs studied. On T lymphoblasts and SFL, mostly CD45RO+ cells, the expression of the beta1 activation-dependent epitope detected by HUTS21 MAb was significantly decreased by aceclofenac, diclofenac, and indomethacin.

CONCLUSION

Some NSAIDs are able to inhibit the adhesion of PBL to HUVEC under conditions that resemble blood flow by interfering with the conformational change in VLA-4 that increases its affinity for VCAM-1.

Inhibition of leukocyte adhesion: an alternative mechanism of action for anti-inflammatory drugs

It has been widely accepted that the mechanism of action of nonsteroidal anti-inflammatory drugs (NSAIDs) is the inhibition of prostaglandin synthesis. However, a significant body of evidence suggests that NSAIDs have additional anti-inflammatory mechanisms of action. Here, Federico Díaz-González and Francisco Sánchez-Madrid discuss novel effects of NSAIDs on leukocyte adhesion pathways that may help in the development of new anti-inflammatory agents that selectively block cell adhesion molecules.