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F Díaz-González

Publications and source records attributed to F Díaz-González.

18 recordsLinked to original sources
PubMed2000

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.

Adenosine Triphosphate↗
PubMed1999

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.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1998

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.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1998

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.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1998

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.

Anti-Inflammatory Agents↗
PubMed1997

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

OBJECTIVE: To explore the effect of the nonsteroidal antiinflammatory drugs (NSAIDs) piroxicam and meloxicam on quantitative and qualitative changes in leukocyte adhesion receptors induced by cytokines and other activation stimuli. METHODS: The expression of CD11b and L-selectin during neutrophil activation with tumor necrosis factor alpha (TNF alpha), granulocyte-macrophage colony-stimulating factor (GM-CSF), FMLP, phorbol myristate acetate (PMA), and calcium ionophore A23187 was assessed by flow cytometry. Enzyme-linked immunosorbent assays were used to quantitate soluble L-selectin shed after neutrophil stimulation. Enzyme release was measured to determine neutrophil degranulation by proinflammatory stimuli. Changes in affinity state of beta 1 and beta 2 integrins after neutrophil and T lymphocyte stimulation were assessed, by flow cytometry, using the monoclonal antibodies (MAb) HUTS-21 (anti-beta 1) and CBRM1/5 (anti-CD11b), which recognize activation-dependent epitopes on these two integrins. RESULTS: Pretreatment of neutrophils with either NSAID prevented the changes in L-selectin and CD11b expression induced by TNF alpha, GM-CSF, and FMLP, but not those induced by PMA or A23187. Furthermore, piroxicam significantly decreased the amount of L-selectin shed by cytokine-treated neutrophils, whereas it did not exert this effect on PMA- or A23187-treated neutrophils. Piroxicam also decreased the release of gelatinase and lysozyme induced by TNF alpha, but not by PMA. Interestingly, piroxicam prevented the conformational changes that beta 2 integrins underwent upon activation of neutrophils: the appearance of the activation epitope of CD11b, detected by the CBRM1/5 MAb, was blocked by piroxicam in TNF alpha-treated neutrophils. Moreover, in chemokine-treated T lymphocytes, the expression of activation epitopes on beta 1 integrins was also diminished by piroxicam. In contrast, this NSAID did not affect the beta 1 integrin conformational changes induced by PMA or Mn++. CONCLUSION: Our results indicate that members of the oxicam family are able to interfere with events of neutrophil function, such as their degranulation and cytokine-mediated activation changes in adhesion molecules, both in neutrophils and in lymphocytes. Such effects may significantly contribute to the antiinflammatory activity of these drugs.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1996

Trans-dominant inhibition of integrin function.

Occupancy of integrin adhesion receptors can alter the functions of other integrins and cause partition of the ligand-occupied integrin into focal adhesions. Ligand binding also changes the conformation of integrin extracellular domains. To explore the relationship between ligand-induced conformational change and integrin signaling, we examined the effect of ligands specific for integrin alpha IIb beta 3 on the functions of target integrins alpha 5 beta 1 and alpha 2 beta 1. We report that binding of integrin-specific ligands to a suppressive integrin can inhibit the function of other target integrins (trans-dominant inhibition). Trans-dominant inhibition is due to a blockade of integrin signaling. Furthermore, this inhibition involves both a conformational change in the extracellular domain and the presence of the beta cytoplasmic tail in the suppressive integrin. Similarly, ligand-induced recruitment of alpha IIb beta 3 to focal adhesions also involves a conformational rearrangement of its extracellular domain. These findings imply that the ligand-induced conformational changes can propagate from an integrin's extracellular to its intracellular face. Trans-dominant inhibition by integrin ligands may coordinate integrin signaling and can lead to unexpected biological effects of integrin-specific inhibitors.

Animals↗
PubMed1996

Aceclofenac, a new nonsteroidal antiinflammatory drug, decreases the expression and function of some adhesion molecules on human neutrophils.

OBJECTIVE: To study the effect of aceclofenac, a new nonsteroidal antiinflammatory drug (NSAID), on the expression and function of adhesion molecules in human neutrophils. METHODS: We used flow cytometry analysis to determine peripheral blood neutrophil expression of L-selectin, CD11a, CD11b, CD31, CD43, CD44, and intercellular adhesion molecule 2 (ICAM-3) surface adhesion molecules after treatment with aceclofenac, diclofenac, or dexamethasone. Granular enzyme activity was quantitated in extracellular medium of neutrophils treated with different NSAID: In vitro adhesion assays were developed to examine the effects of aceclofenac on both neutrophil adhesion to tumor necrosis factor alpha stimulated human umbilical vein endothelial cells under nonstatic conditions, and homotypic neutrophil aggregation induced by anti-ICAM-3 and anti-CD18 monoclonal antibodies (Mab). RESULTS: Aceclofenac induced a dramatic decrease of L-selectin expression, whereas a moderate and slight decrement of CD43 and ICAM-3 expression was also observed. In contrast, the expression of other adhesion molecules by neutrophils was unaffected (CD11a, CD31, CD44) or slightly increased (CD11b). Cell adhesion assays, performed under nonstatic conditions, revealed that aceclofenac significantly diminished the L-selectin dependent neutrophil adhesion to endothelial cells. Neutrophil aggregation induced with anti-CD43 Mab was also significantly inhibited by aceclofenac. CONCLUSION: Aceclofenac had a faster and more potent effect than the other NSAID studied, mainly on the expression of cell adhesion molecules. This new NSAID efficiently interferes with neutrophil adhesion to endothelium and this effect may represent an additional relevant mechanism in its antiinflammatory activity.

Anti-Inflammatory Agents↗
PubMed1995

Prevention of in vitro neutrophil-endothelial attachment through shedding of L-selectin by nonsteroidal antiinflammatory drugs.

The activation of the endothelial cells by extravascular stimuli is the key event in the extravasation of circulating leukocytes to target tissues. L-selectin, a member of the selectin family, is constitutively expressed by white cells, and is the molecule involved in the initial binding of leukocytes to activated endothelium. After activation, leukocytes rapidly release L-selectin from the cell surface, suggesting that the functional activity of this molecule is controlled in large part by its appearance and disappearance from cell surface. We have studied in a neutrophil-activated endothelial cell binding assay, the effect of different antiinflammatory drugs (steroidal and nonsteroidal) in the L-selectin-mediated interaction of neutrophils with activated endothelial cells. Some nonsteroidal antiinflammatory drugs (NSAIDs), such as indomethacin, diclofenac, ketoprofen, and aspirin, but not steroids, strongly inhibited the neutrophil-endothelial cell attachment. Furthermore, we also investigated the underlying mechanism of this functional effect. The expression of L-selectin on the neutrophil surface rapidly decreased in the presence of different NSAIDs, in a dose- and time-dependent manner, whereas no changes in the expression of other adhesion molecules such as CD11a, CD11b, CD31, or ICAM-3 (CD50) were observed. Interestingly, studies in vivo on healthy volunteers treated with physiological doses of indomethacin showed a significant decrease of L-selectin neutrophil expression. Only diclofenac induced an upregulation of CD11b expression, suggesting an activating effect on neutrophils. No enzyme release was observed upon treatment of neutrophils with different NSAIDs, indicating a lack of degranulatory activity of NSAIDs, with the exception of diclofenac. The downregulation of L-selectin expression was due to the rapid cleavage and shedding of the membrane L-selectin, as determined by both immunoprecipitation from 125I-labeled neutrophils, and quantitative estimation in cell-free supernatants. These results suggest that NSAIDs exert a specific action on adhesion receptor expression in neutrophils, which might account, at least in part, for the antiinflammatory activities of NSAIDs.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1994

Expression of L-selectin, CD43, and CD44 in synovial fluid neutrophils from patients with inflammatory joint diseases. Evidence for a soluble form of L-selectin in synovial fluid.

OBJECTIVE: To study the expression of L-selectin, CD43, and CD44 on peripheral blood (PB) and synovial fluid (SF) neutrophils from patients with inflammatory joint diseases, and to investigate the presence of soluble L-selectin in both SF and plasma from patients with acute and chronic arthritis. METHODS: PB and SF neutrophils were isolated from 13 patients with rheumatoid arthritis (RA) and 17 patients with various inflammatory joint diseases other than RA. Expression of L-selectin, CD43, CD44, CD11a, and CD11b was determined in both unstimulated and in vitro-activated cells by immunofluorescence flow cytometry. Soluble L-selectin levels were estimated in SF and plasma by a semiquantitative radioimmunoassay. RESULTS: Neutrophils from SF showed diminished expression of L-selectin compared with PB neutrophils; CD43 expression and CD44 expression were decreased in SF neutrophils from most patients. In contrast, SF neutrophils exhibited significantly increased expression of CD11b, to an extent similar to that seen with in vitro-activated PB neutrophils. Soluble L-selectin was detected at similar levels in SF and PB. CONCLUSION: The phenotypic profile of SF neutrophils (low levels of L-selectin, CD43, and CD44, and high levels of CD11b) from most patients with RA or other inflammatory joint conditions resembles that observed in in vitro-activated neutrophils. Our results suggest that SF neutrophils are activated to a similar degree in inflammatory joint diseases with different pathogenic mechanisms.

Acute Disease↗
PubMed1994

Adhesion molecules from the LFA-1/ICAM-1,3 and VLA-4/VCAM-1 pathways on T lymphocytes and vascular endothelium in Graves' and Hashimoto's thyroid glands.

Lymphocytic infiltration of the thyroid gland in autoimmune thyroid disorders requires, as a first step, their attachment to endothelial cells (EC) and subsequently, their interaction with thyrocytes and extracellular matrix proteins. A number of different ligand molecules have been identified to mediate the interaction between EC and leukocyte subpopulations. In this study, we examined by flow cytometry and immunohistochemical techniques, the expression of integrin receptors and their counter-receptors by infiltrating lymphocytes and vascular endothelium in thyroid glands from patients with Graves' disease (GD) and Hashimoto's thyroiditis (HT). A high proportion of GD intrathyroidal T lymphocytes expressed the CD69 and gp95/85 (Ea2) activation antigens as well as an increased number of LFA-alpha L, VLA-alpha 1, -alpha 4, -alpha 5, and beta 1 integrin receptors, as compared with peripheral blood T lymphocytes from the same patients. The expression of intercellular adhesion molecule (ICAM)-1 was increased in EC from GD and HT thyroids. In addition, an up-regulated de novo expression of vascular cell adhesion molecule (VCAM)-1 was found in EC in GD and HT thyroids, with no reactivity in control thyroids. Dendritic cells in thyroid lymphoid follicles were also positive for ICAM-1 and VCAM-1. In addition, most of intrathyroidal mononuclear cells expressed the ICAM-3 adhesion molecule. This enhanced expression of ICAM-1 and VCAM-1 by thyroid EC in GD and HT may reflect their ability to regulate leukocyte trafficking and activation by means of the expression of specific ligand molecules. Our data suggest that both the LFA-1/ICAM-1, ICAM-3 and VLA-4/VCAM-1 pathways could play a relevant role in localizing and perpetuating the autoimmune response in the thyroid gland in autoimmune thyroid disorders.

Antigens, CD↗
PubMed1990

Rheumatoid disease resembling lung neoplasia.

We describe a 67-year-old man with severe rheumatoid arthritis of long duration. He developed a peculiar extraarticular rheumatoid complication consisting of localized lung consolidation with a pathological costal fracture, together with an abrupt systemic reaction that occurred in the course of immunosuppressive treatment. The diagnosis first proposed was lung cancer with costal metastases. However exhaustive studies performed in the search of malignancy were systematically negative and pathologic studies finally demonstrated bronchiolitis obliterans with organizing pneumonia (BOOP) as responsible for parenchymal lung consolidation with a rheumatoid nodule eroding bone at the level of the rib fracture. These findings, after long followup of the patient, attest to the rheumatoid origin of his bizarre manifestations and definitely rule out a neoplastic etiology.

Aged↗
PubMedDate not supplied

Dual positivity for cytoplasmic and perinuclear anti-neutrophil antibodies in a patient with Henoch-Schönlein purpura.

We herein describe the case of a 60-year-old man who presented clinical and histopathological evidence of Henoch-Schönlein purpura. Antineutrophil antibodies (ANCA) showed positive results on an enzyme-linked immunosorbent assay and immunofluorescence for anti-myeloperoxidase and anti-proteinase 3 antibodies. Dual positivity for both cytoplasmatic (C-ANCA) and perinuclear (P-ANCA) antineutrophil antibodies has been found previously in a small number of reports, but to our knowledge this is the first time the simultaneous presence of C-ANCA and P-ANCA has been observed in Henoch-Schönlein purpura.

Antibodies, Antineutrophil Cytoplasmic↗