C. Vilardell

Elevated Production of Interleukin-6 Is Associated With a Lower Incidence of Disease-Related Ischemic Events in Patients With Giant-Cell Arteritis. Angiogenic Activity of Interleukin-6 as a Potential Protective Mechanism

Background—Patients with giant-cell arteritis (GCA) who develop a strong acute-phase response are at low risk of disease-related ischemic events. Methods and Results—To assess the potential protective role of proinflammatory cytokines in the development of ischemic events in GCA, we measured tissue expression (66 individuals) and/or circulating levels (80 individuals) of interleukin (IL)-1&bgr;, tumor necrosis factor-&agr; (TNF-&agr;), and IL-6 in patients with biopsy-proven GCA. Tissue expression was determined by quantitative real-time polymerase chain reaction and immunohistochemistry. Circulating cytokines were determined by enzyme-linked immunoassay. We found that patients with disease-related ischemic events had lower IL-6 mRNA levels (5.9±2.1 versus 27.6±7.8 relative units, P =0.013), lower IL-6 immunohistochemical expression scores (1.5±0.9 versus 2.7±1, P =0.001), and lower circulating levels of IL-6 (13.6±2.1 versus 24±2.4 pg/mL, P =0.002) than patients without ischemic complications. No significant differences were found for either IL-1&bgr; or TNF-&agr;. We subsequently investigated direct effects of IL-6 on vessel wall components. We found that IL-6 stimulates endothelial cell proliferation and differentiation into capillary-like structures and induces full angiogenic activity in both ex vivo (aortic ring) and in vivo (chick chorioallantoic membrane) assays. Conclusions—GCA patients with ischemic complications have lower tissue expression and circulating levels of IL-6 than patients with no ischemic events. IL-6 has relevant direct effects on vascular wall components that might be protective: IL-6 activates a functional program related to angiogenesis that may compensate for ischemia in patients with GCA.

Dual function of focal adhesion kinase in regulating integrin-induced MMP-2 and MMP-9 release by human T lymphoid cells

SPECIFIC AIMSThe aim of our study was to assess the role of focal adhesion kinase (FAK) in integrin-mediated gelatinase production by T lymphoid cells.PRINCIPAL FINDINGS1. FAK regulates integrin-de...

Circulating soluble adhesion molecules in patients with giant cell arteritis. Correlation between soluble intercellular adhesion molecule-1 (sICAM-1) concentrations and disease activity.

OBJECTIVE To evaluate whether changes in concentrations of circulating adhesion molecules are related to disease activity in patients with giant cell arteritis (GCA). METHODS A sandwich ELISA was used to measure soluble intercellular adhesion molecule-1 (sICAM-1), sICAM-3, vascular cell adhesion molecule-1 (sVCAM-1), E-selectin (sE-selectin), and L-selectin (sL-selectin) in serum and plasma samples from patients with GCA. A cross sectional study was performed on 64 GCA patients at different activity stages and on 35 age and sex matched healthy donors. Thirteen of these patients were evaluated at the time of diagnosis and serially during follow up. RESULTS At the time of diagnosis, sICAM-1 concentrations were significantly higher in active GCA patients than in controls (mean (SD) 360.55 (129.78) ng/ml versus 243.25 (47.43) ng/ml, p<0.001). In contrast, sICAM-3, sVCAM-1, sE-selectin, and sL-selectin values did not differ from those obtained in normal donors. With corticosteroid administration, a decrease in sICAM-1 concentrations was observed, reaching normal values when clinical remission was achieved (263.18 (92.7) ng/ml globally, 293.59 (108.39) ng/ml in the group of patients in recent remission, and 236.83 (70.02) ng/ml in those in long term remission). In the 13 patients followed up longitudinally, sICAM-1 values also normalised with clinical remission (225.87 (64.25) ng/ml in patients in recent remission, and 256.29 (75.15) ng/ml in those in long term remission). CONCLUSIONS Circulating sICAM-1 concentrations clearly correlate with clinically apparent disease activity in GCA patients. Differences with results previously found in patients with other vasculitides may indicate that different pathogenic mechanisms contribute to vascular inflammation in different disorders.

Regulation of ICAM-3 and other adhesion molecule expressions on eosinophils in vitro. Effects of dexamethasone

Background: ICAM‐3 has been recently identified as the third leukocyte‐function associated‐1 (LFA‐1) ligand. ICAM‐3 is expressed in eosinophils, but its regulation has not been studied. The objective of this study was to investigate the differential expression of ICAM‐3 and other adhesion molecules (AM) on the surface of eosinophils. We also evaluated the effects of dexamethasone on AM expression.

Thalidomide decreases gelatinase production by malignant B lymphoid cell lines through disruption of multiple integrin-mediated signaling pathways

Background Thalidomide and its analogs are effective agents in the treatment of multiple myeloma. Since gelatinases (matrix metalloproteinases-2 and -9) play a crucial role in tumor progression, we explored the effect of thalidomide on gelatinase production by malignant B lymphoid cell lines. Design and Methods We investigated the effect of therapeutic doses of thalidomide on integrin-mediated production of gelatinases by malignant B lymphoid cell lines by gelatin zymography, western-blot, reverse transcriptase polymerase chain reaction and invasive capacity through Matrigel-coated Boyden chambers. We also explored the effect of thalidomide on the activation status of the main signaling pathways involved in this process. Results Thalidomide strongly inhibited gelatinase production by B-cell lines and primary myeloma cells in response to fibronectin, the most efficient gelatinase inducer identified in lymphoid cells. Thalidomide disrupted integrin-mediated signaling pathways involved in gelatinase induction and release, such as Src and MAP-kinase ERK activation, resulting in decreased cell motility and invasiveness. Unexpectedly, treatment with thalidomide elicited an increase in fibronectin-induced Akt phosphorylation through phosphoinositide 3-kinase-independent pathways since thalidomide decreased fibronectin-induced phosphoinositide 3-kinase phosphorylation and reversed the inhibition of Akt phosphorylation achieved by the phosphoinositide 3-kinase inhibitors wortmannin and LY294002. Conclusions Disruption of integrin-mediated signaling may be an important mechanism through which thalidomide and its analogs impair tumor cell interactions with the microenvironment. The unexpected effects of thalidomide on Akt activation indicate the need for further studies to elucidate whether the interference with Akt downstream effects would synergize with the anti-tumor activity of thalidomide.

Human T-cell response to L14 pig cell line transfected with human ligands CD80 and CD86.

MATERIALS AND METHODSIrradiated L14, a B lymphoblastoid pig cell line, was used asstimulator, and human monocyte highly depleted peripheral bloodcells (MHDC) were used as responder cells. Proliferation wasmeasured by H3-Thymydine. IL-2 was measurement in superna-tants by ELISA (Immunotech) at 48 hours. L14 cell line wastransfected separately by electrophoration with hCD80, hCD86,and hICAM1(CD54) using plasmidic vector PCDNA3, which pro-duces a stable transfection. The transfected cells were grown onselective media and cloned by limiting dilution. Three clones wereselected by its high expression of the human antigens: L14-hCD80(5), L14-hCD86(13), and L14-hICAM1(10).RESULTS