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Objective: The aim of the study was to investigate LDL modifications by cultured human umbilical vein endothelial cells (HUVEC) from women smokers and non-smokers. Methods: Modifications of LDL by HUVEC were studied by determining the values of thiobarbituric acid-reactive substances (TBARS) and the percentage of the most electronegative oxidized LDL fraction (fraction C) by using an ion-exchange chromatographic method based on fast protein liquid chromatography (FPLC). We also studied the cellular production of superoxide anion, the effect of various inhibitors and cysteine, and determined total intracellular glutathione content and cell growth. Results: LDL exposed to HUVEC from smokers for 48 h showed significantly greater modifications than LDL exposed to HUVEC from non-smokers, as assessed by TBARS determination (19.4 ± 1.2, mean ± s.e.m., n = 20 versus 15.4 ± 0.7 nmol/mg LDL, n = 19; P < 0.01) and by FPLC (percentage of fraction C: 39 ± 7, n = 29 versus 14 ± 3, n = 34; P < 0.001). Moreover, HUVEC from smokers produced significantly more superoxide anion than those from non-smokers (0.46 ± 0.13 nmol/105 cell/min, n = 9 versus 0.22 ± 0.05, n = 10; P < 0.05). Superoxide production, like cell-induced modification of LDL, was strongly dependent on the presence of cysteine in the medium. Furthermore, HUVEC from smokers had a significantly (P < 0.05) higher total intracellular glutathione content than those from non-smokers (39.9 ± 3.1 nmol/mg, n = 9 versus 31.8 ± 2.2, n = 7). Finally, HUVEC from smokers and non-smokers showed similar growth at 48 h. Conclusion: HUVEC from smokers converted significantly more LDL into an atherogenic form than HUVEC from non-smokers, a phenomenon that was not due to altered cell growth. HUVEC-mediated LDL modifications were strongly thiol-dependent, as both LDL modifications and superoxide anion production were inhibited in cysteine-free medium. Stimulation of cystine uptake by HUVEC, reflected by the enhanced total glutathione content, could account for the enhanced superoxide anion production. All these observations may be relevant to the pathophysiology of smoking-related cardiovascular disease. [ABSTRACT FROM PUBLISHER]

Cyclosporine A (CsA) is a widely used immunosuppressant which possesses significant side effects including nephrotoxicity and systemic arterial hypertension. In this work we evaluated the effects of CsA on human umbilical endothelial cell proliferation (HUVEC). Treatment of endothelial cells with CsA inhibited cell proliferation, and was correlated with an increase of interleukin-6 (IL-6) production and IL-6 mRNA expression. Addition of exogenous IL-6 also significantly altered cell proliferation. Furthermore, neutralization of endogenous IL-6 with a specific monoclonal antibody concomitantly with CsA treatment completely restored HUVEC proliferation. These results suggest that CsA-induced inhibition of HUVEC proliferation is mediated through an augmentation of IL-6 synthesis.

Immunoglobulin abnormalities in serum from 76 heart-transplant recipients were examined by cellulose acetate and agarose gel electrophoresis. Monoclonal components were typed by immunofixation. IgG, IgA, and IgM and total kappa and lambda light chains were quantified by immunonephelometry. We confirm that both monoclonal and oligoclonal immunoglobulin banding are common in serum from these patients. Of the 149 serum samples examined, 21 (15%) had one monoclonal component and 53 (35%) had two or more. These monoclonal immunoglobulins were generally present at a low concentration and were transient. The class of immunoglobulins most commonly involved was IgG (about sevenfold more numerous than IgM); monoclonal IgA components and free light chains were not detected. The nephelometric kappa/lambda and heavy chain/light chain ratios were poor indicators of these abnormalities. Immunoglobulin abnormalities were not correlated with the sex and age of recipients, the pre-existing cardiopathy, the time since transplantation, or plasma concentrations of cyclosporine, but did correlate with plasma immunoglobulin concentration, biopsy findings, and viral infections, especially cytomegalovirus (CMV). A monoclonal IgG purified from a patient with a high titer of anti-CMV antibodies did not react with CMV antigens. The origin of these immunoglobulin abnormalities is unclear. Our data suggest that the presence of monoclonal or oligoclonal banding in heart-transplant recipients is of limited prognostic significance.