A bronchial epithelial cell-derived factor in asthma that promotes eosinophil activation and survival as GM-CSF

We have examined the in vitro interaction between bronchial epithelial cells and eosinophils derived from five asthmatics by determining the effect of epithelial cell-conditioned medium on the survival and activation of peripheral blood eosinophils. The supernatants of epithelial cells from six normal donors were used as control. The asthmatic epithelial cell-conditioned medium significantly increased the survival of eosinophils cultured for 3 (P less than 0.025) and 6 (P less than 0.05) days. The incubation of eosinophils with the supernatants of asthmatic epithelial cells for 1 h also increased the generation of superoxide anion and the release of leukotriene C4, triggered by phorbol myristate acetate and calcium ionophore, by more than twofold. The preincubation of asthmatic epithelial cell-conditioned media with saturating concentrations of a mono-specific antiserum against granulocyte-macrophage colony-stimulating factor (GM-CSF) completely abolished their activity, whereas the addition of recombinant human GM-CSF restored it. The supernatants of asthmatic epithelial cells contained 0.88 +/- 0.09 (SD) ng/5 X 10(5) cells immunoreactive GM-CSF, and this amount was significantly greater than that measured in the supernatants of normal epithelial cells (0.21 +/- 0.105, P less than 0.025). Bronchial epithelial cells from asthmatics also expressed increased levels of GM-CSF mRNA when compared with normal epithelial cells. Thus both the synthesis and release of GM-CSF by bronchial epithelial cells are upregulated in asthma, and this may contribute to the persistence of eosinophil infiltration and activation in asthmatic airways.

Human bronchial epithelial cells modulate CD3 and mitogen-induced DNA synthesis in T cells but function poorly as antigen-presenting cells compared to pulmonary macrophages

This study was undertaken to investigate the ability of bronchial epithelial cells (ECs) to function as accessory cells. Pulmonary monocytes were our reference cells. ECs and pulmonary monocytes were isolated from the bronchial mucosa and pulmonary parenchyma of subjects undergoing lobectomy for standard clinical reasons. Circulating autologous T cells were rigorously depleted of accessory cells to the extent that they lost the capacity to respond to mitogenic lectins alone. ECs restored mitogen-induced DNA synthesis and DNA synthesis triggered by CD3 cross-linking in T cells, as did pulmonary macrophages, and this was unrelated to HLA-DR expression. The ability of promoting T cell proliferation after CD3 cross-linking was, in part, due to the secretory products of ECs, since their supernatants were also effective. Interferon-gamma-treated ECs were capable of presenting antigens to autologous T cells. This was an HLA-DR-restricted phenomenon, but EC efficiency in this system was less than 40% of efficiency demonstrated by pulmonary monocytes. However, ECs greatly upregulated antigen-specific responses supported by pulmonary monocytes.

Cellular and biochemical characteristics of bronchoalveolar lavage fluid in symptomatic nonallergic asthma

We have undertaken cellular and biochemical examination of bronchoalveolar lavage fluid from nonallergic patients with asthma to determine the nature and degree of inflammatory process in symptomatic asthma. Six patients with asthma (mean methacholine provocative concentration causing a 20% fall in FEV1 was 0.26 mg/ml) and six control subjects underwent fiberoptic bronchoscopy with bronchoalveolar wash. The patients with asthma shed a higher number of epithelial cells into lavage fluid than normal control subjects (p less than 0.05). Their lavage fluid also contained increased numbers of neutrophils (p less than 0.025), eosinophils (p less than 0.025), and basophilic cells (p less than 0.025), and increased proportion of activated T cells (p less than 0.05). The basophilic cells were mast cells, as indicated by positive labeling with the monoclonal antibody MCG35. Biochemical analysis of lavage fluid demonstrated exudation of protein molecules in airways of patients with asthma with increased contents of albumin (p less than 0.05) and fibronectin (p less than 0.05). In the lavage fluid of patients with asthma, there were also increased amounts of interleukin-1-beta (IL-1-beta) (p less than 0.025), interleukin-6 (IL-6) (p less than 0.025), and granulocyte-macrophage, colony-stimulating factor (GM-CSF) (p less than 0.05), as compared with lavage fluid of normal control subjects. Immunocytochemical evaluation of lavage cells demonstrated that IL-1-beta, IL-6, and GM-CSF were mostly produced by nonciliated epithelial cells and/or monocytes. IL-1, IL-6, and GM-CSF can prime granulocytes to respond to other stimuli and can promote T cell activation.(ABSTRACT TRUNCATED AT 250 WORDS)

The protective effect of frusemide on the generation of superoxide anions by human bronchial epithelial cells and pulmonary macrophages in vitro

Inhaled frusemide has been shown to inhibit bronchoconstriction induced by immunological and nonimmunological stimuli in asthmatic patients. The mechanisms by which this compound exerts its effect in asthmatic airways are unknown, but an inhibitory action on the activation of inflammatory cells or on the responsiveness of sensory epithelial nerves may be involved. In this study, we give evidence that frusemide prevents in part the activation of bronchial epithelial cells and pulmonary macrophages, as it reduces the rate of superoxide anion generation induced by IgE receptor cross-linking and by phorbol myristate acetate by 40-60%. The effect was not specific since we used stimuli which activate different signal transduction pathways for NADPH oxidase stimulation and frusemide was equally effective.

Bronchial epithelial cells exposed to isocyanates potentiate activation and proliferation of T-cells

Bronchial epithelial cells release chemotactic factors for lymphocytes and express HLA-DR antigens. Thus they may contribute to the T-cell-mediated inflammatory responses involved in a number of pulmonary diseases such as asthma. In this study, the in vitro exposure of human bronchial epithelial cells to toluene 2,4-diisocyanate (TDI), an inflammatory and asthmogenic stimulus presumed to act at least in part through immunological mechanisms, provoked cell damage followed by proliferation of the cells that survived the injury. At the time of the proliferative response, epithelial cells released factors that upregulated the activation and proliferation of T lymphocytes presensitized by antigen receptor triggering. The T-cell activating factors were interleukin (IL) 1- and 6-like substances, as demonstrated by the ability of specific antisera to inhibit most of the biological effect, and by the ability of recombinant IL-1 and IL-6 to reproduce it. Appreciable amounts of immunoreactive IL-1 and IL-6 were indeed recovered in the supernatants of TDI-exposed epithelial cells. The release of these cytokines may represent an important mechanism by which epithelial cells respond to some environmental stimuli and contribute to the persistence of inflammatory responses in the airways.

Specific binding of endothelin on human bronchial smooth muscle cells in culture and secretion of endothelin-like material from bronchial epithelial cells

Endothelin, synthesized by endothelial cells, is the most potent vasoconstrictor and bronchoconstrictor agent known. We investigated endothelin release from human bronchial epithelial cells and the binding of the peptide to autologous bronchial smooth muscle cells in culture. Epithelial and smooth muscle cells were isolated by enzymatic digestion of bronchial tissue obtained on surgery, and cultured to confluency by standard methods. Epithelial cells stained positively for cytokeratin filaments. Smooth muscle cells stained uniformly for alpha-smooth muscle actin. Immunoreactive endothelin contents in the supernatants of epithelial cells extracted on C8 Amprep columns were evaluated by radioimmunoassay. Epithelial cells released appreciable amounts of immunoreactive endothelin into the culture medium (from 0.65 to 2.1 pmol/ml). A single specific binding site for [125I]endothelin 1 was identified on bronchial smooth muscle cells with an apparent Kd of 113 pM and a maximal binding capacity of 22.1 fmol/10(6) cells. At room temperature the binding was saturable, reached equilibrium at 120 min (25 pM endothelin 1), and was slowly and incompletely reversed by unlabeled endothelin over a period of 8 h. Conditioned medium from epithelial cells inhibited the [125I]endothelin 1 binding, dose dependently, and the effect was antagonized by monospecific antiserum. Thus, human bronchial smooth muscle cells possess specific binding sites for endothelin 1 and human bronchial epithelial cells secrete an endothelin-like material. This may have a role in the pathogenesis of asthma.

Effects of serum storage on the determination of cholesterol

Cholesterol determined by 4 different enzymatic commercial kits and by the dry chemistry Reflotron system was higher in serum stored at 4 degrees C and at -20 degrees C than in fresh serum. The effects of storage seem to be temperature-dependent. In fact, cholesterol values significantly increased only after 2h of freezing. The prolongation of freezing up to 2 weeks was not followed by further significant changes. In serum stored at 4 degrees C the increase in cholesterol was slower than in frozen serum. Both free and esterified cholesterol underwent an increase after storage. When cholesterol was determined by a chemical method (sulfuric acid-ferric chloride) after extraction with ethyl acetate and ethanol, no difference was observed in fresh and stored serum. Cholesterol, triglycerides and apoproteins A-I and B underwent parallel changes after storage both in whole serum and fractionated lipoproteins. Our findings strongly suggest that in serum stored at positive or negative temperature there is an alteration of the lipoprotein molecules which allows an easier availability of cholesterol for the enzyme-substrate reaction than in fresh serum. Current enzymatic methods underestimate (about 10%) cholesterol when the analysis is performed on fresh serum.

Nedocromil sodium prevents the release of 15-hydroxyeicosatetraenoic acid from human bronchial epithelial cells exposed to toluene diisocyanate in vitro

The in vivo exposure to an asthmogenic stimulus, toluene diisocyanate (TDI), causes airway epithelial damage associated with inflammation and increased bronchial hyperresponsiveness. The latter mechanisms might partly be mediated by the release of eicosanoids from bronchial epithelial cells. We have previously demonstrated that the in vitro exposure of bronchial epithelial cells to TDI results in the release of immunoreactive 15-hydroxyeicosatetraenoic acid (15-HETE), a product of activation of the 15-lipoxygenase pathway with inflammatory properties. In the present study we show that TDI-induced release of 15-HETE from epithelial cells can be prevented by nedocromil sodium, an anti-asthmatic drug with anti-inflammatory properties. This mode of action of the compound may explain its clinical effectiveness in asthma.

Inhibition of cholesterol biosynthesis in freshly isolated blood mononuclear cells from normolipidemic subjects and hypercholesterolemic patients treated with bezafibrate

Bezafibrate was given for 15 days at a dose of 200 mg t.i.d. to 4 normolipidemic subjects, to 5 patients with putative heterozygous familial hypercholesterolemia, and to 6 patients with primary hypercholesterolemia of the non-familial type. At the end of the treatment, the rate of incorporation of labelled acetate into non-saponifiable lipids in freshly isolated blood mononuclear cells decreased in all subjects. On the average, acetate incorporation decreased by 31% in cells from normolipidemic subjects, 41% in cells from familial, and 45% in cells from non-familial hypercholesterolemia patients. Results of the present study suggest that the lowering effect of bezafibrate on serum cholesterol is mainly due to the inhibition of cholesterol synthesis through the suppression of HMG-CoA reductase as was demonstrated in rat hepatocytes and in cultured human blood mononuclear cells.

Bezafibrate inhibits HMG-CoA reductase activity in incubated blood mononuclear cells from normal subjects and patients with heterozygous familial hypercholesterolaemia

In incubated blood mononuclear cells from normal subjects bezafibrate inhibited the incorporation of 14C-acetate into squalene, methylsterols and cholesterol. Similarly, the drug produced a sharp decrease of the incorporation of labelled 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) into non-saponifiable lipids, while the incorporation of 14C-mevalonate was unaffected by the presence of bezafibrate in the incubation mixture. This strongly suggests that bezafibrate inhibits HMG-CoA reductase activity. In cultured cells from patients with heterozygous familial hypercholesterolaemia the presence of bezafibrate in the incubation medium resulted in an inhibition of the incorporation of labelled acetate into non-saponifiable lipids. Bezafibrate then inhibits cholesterol biosynthesis in cells from normal and hypercholesterolaemic patients and this effect is likely, to contribute to the hypocholesterolaemic activity of the drug.

Cholesterol distribution between HDL subfractions. A study of 498 subjects

In 498 subjects (205 normolipidemics and 293 hyperlipidemics) of both sexes, the cholesterol content of high density lipoprotein (HDL) subfractions has been determined. The serum concentration of total HDL-cholesterol appears to be more strictly related to the cholesterol content of HDL2 than to that of HDL3. This latter one, however, gives a contribution to the variability of HDL-cholesterol so that the value of HDL-cholesterol cannot be assumed as a reliable estimate of the serum level of the more anti-atherogenic HDL2 subfraction. The cholesterol content of HDL and its subfractions is higher in women than in men and decreases with increasing serum VLDL-cholesterol level and body weight. Both HDL2- and HDL3-cholesterol appear to largely depend from the metabolism of triglyceride-rich lipoproteins in accordance with the data of experimental studies.

Relationship of serum triglyceride concentration to lipoprotein composition and concentration in normolipidemic and hyperlipidemic subjects

In a series of 438 subjects (184 normolipidemics and 254 hyperlipidemics) the relationship among serum concentration of triglycerides, lipoprotein lipids and apoproteins A-I and B has been evaluated. The results show that as serum triglyceride level increases, VLDL rise and become enriched in triglycerides. The increase of VLDL is associated with a reduction of serum levels of LDL and HDL which appear to be rich in triglycerides and poor in cholesterol. The decrease in serum HDL level is mainly due to a reduction in serum concentration of the HDL2 subfraction. The triglyceride content of HDL2 and HDL3 rises with increasing serum triglycerides. The increase in serum triglyceride concentration seems then to be associated with a complex metabolic derangement which involves all the lipoprotein fractions.

Changes in the serum lipoprotein pattern induced by two low-fat diets with a different vegetable content in hypercholesterolemic patients

Thirty-two hypercholesterolemic outpatients were treated by a conventional low-fat diet (carbohydrate 56%; fat 25%; vegetable proteins 7%; animal proteins 12% of energy; P/S ratio 1.0). After 1 month T-C decreased by 11%, VLDL-C by 32%, LDL-C by 8%, HDLt-C by 10% and HDL2-C by 11%. Thirty-two comparable patients were treated by a different low-fat diet which provided 69% of energy as carbohydrate, 19% as fat, 7% as vegetable proteins and 5% as animal proteins; P/S ratio was 1.3. After 1 month T-C decreased by 9% and LDL-C by 12%. VLDL-C, HDL2-C and HDL3-C did not change significantly. A cross-over study on 24 patients confirmed that both diets have lowering effects on T-C and LDL-C levels, but only the conventional low-fat diet decreases VLDL-C and HDL2-C.

Long-term effects of fenofibrate on serum lipids and on lipoprotein cholesterol in type II hyperlipoproteinemic patients

Twenty two patients with primary type II hyperlipoproteinemia (13 phenotype IIa and 9 phenotype IIb) were treated with fenofibrate 300 mg a day for 4-12 months. Serum total cholesterol decreased, on the average, by 22 per cent and LDL cholesterol by 24 per cent. In the patients with familial hypercholesterolemia, total cholesterol decreased by 28 per cent and LDL cholesterol by 31 per cent. One patient with homozygous familial hypercholesterolemia showed the greatest fall of total and LDL cholesterol (44 and 48 per cent respectively) and this was accompanied by a nearly complete disappearance of xanthelasmas and xanthomas.

Effect of D-glucitol-hexanicotinate on platelet aggregability in patients with coronary heart disease

D-glucitol-hexanicotinate (sorbinicate) was administered at a daily dose of 1.6 mg to 16 male patients who had survived myocardial infarction. Platelet aggregation induced by collagen (5 micrograms/ml), by ADP (2, 1.2, 0.8, and 0.4 X 10(-6)M), and by epinephrine (1 and 0.5 X 10(-6)M) was significantly decreased after 3 months of therapy. In a group of 13 comparable patients, who did not receive sorbinicate, platelet aggregation induced by ADP (1.2, 0.8, and 0.4 X 10(-6)M) and by epinephrine (1 X 10(-5)M and 1 X 10(-6)M) was significantly increased 3 months after entry into the study. Sorbinicate has effective lipid-lowering activity; the combination of hypolipidemic and anti-aggregating properties may prove important in primary and secondary prevention of atherosclerotic disease.

[Significance of certain neoplastic markers in a series of patients with lung cancer]

Perchloric acid soluble proteins (PPS) and their content of N-acetylneuraminic acid (NANA) may serve as valuable tumor markers for a variety of malignant neoplasms. To evaluate their clinical significance, PPS, NANA and carcino-embryonic antigen (CEA) were measured in 32 patients with lung cancer. High PPS (greater than or equal to 0,73 mg/ml) and NANA (greater than or equal to 96 micrograms/ml) levels occurred in 8 of 50 (16%) healthy volunteers and respectively in 22% and 54% of patients. CEA levels were high (greater than or equal to 3 ng/ml) in 1 out of 21 (5%) healthy volunteers and in 83% of the patients; 84% of the patients showed an elevation of NANA and of CEA. The highest values of the three markers seem to be associated with extensive disease but no statistically significant difference has emerged from the comparison of patients with limited disease with the ones with extensive involvement. Changes of the tumor mass correlate with changes of serum levels of PPS, NANA and CEA. It is concluded that CEA determination is clinically valuable in lung cancer, while PPS and NANA do not provide greater information.

Fenofibrate therapy of hypertriglyceridaemia. Differential effects on LDL cholesterol level in type IV and in type IIb primary hyperlipoproteinaemia

Twenty five hypertriglyceridaemic patients (16 Type IV and 9 Type IIb) were treated with fenofibrate 300 mg/d. In Type IV patients serum triglycerides and VLDL cholesterol decreased, while LDL and HDL cholesterol rose significantly. In Type IIb patients, triglycerides and total, VLDL, IDL and LDL cholesterol were significantly reduced by the treatment. The correction of hypertriglyceridaemia by fenofibrate seems, therefore, to induce different changes in lipoproteins in Type IIb and in Type IV hyperlipoproteinaemic patients. The practical implications of these results are discussed.

[Serum lipoproteins and coronary disease in diabetes. Changes in the lipoprotein pattern in relation to the type of antidiabetic therapy]

One hundred and fifty seven maturity-onset diabetics (77 males and 80 females) with coronary heart disease (CHD) were compared with 130 non-CHD diabetic patients (62 males and 68 females) of the same age-range. Integrated mean blood pressure, duration of diabetes, serum triglycerides, beta and prebeta-lipoproteins were significantly higher and alpha lipoproteins significantly lower in CHD than in non-CHD patients. Alpha lipoproteins, duration of diabetes and beta lipoproteins were the variables of highest weight in discriminating CHD from non-CHD patients. Alpha lipoprotein had a greater discriminating power than beta lipoprotein in man, while in women the opposite occurred. In patients on insulin and on sulfonylurea therapy, both with and without CHD, the concentration of alpha lipoproteins, but not of other lipoproteins, was higher than in the corresponding subgroups of the diet-treated patients. However, within each treatment group, patients with CHD had lower alpha lipoproteins.

Effects of intravenous high doses of ketoprofen on blood clotting, bleeding time and platelet aggregation in man

The effect of ketoprofen (Orudis, Farmitalia) on ADP, epinephrine (EPI) and collagen (COLL) induced platelet aggregation (PlA), simplate bleeding time (SBT), partial thromboplastin time (PTT) and per cent prothrombin activity (PrA) was studied in eleven patients, four males and seven females (median age 59 years) with rheumatoid arthritis (six cases), cancer (four cases) and osteoarthrosis (one case). Tests were performed before and 1, 8 and 24 hours after a single intravenous dose (600 mg) of ketoprofen and on Days 4 and 8 during a 7-day treatment (200 mg i.v. every 8 hours) and 1 day after withdrawal of the drug. PTT and PrA were not affected by the drug. Bleeding time was not significantly modified by the acute treatment, but was prolonged during the subacute course, though it was not different from baseline values at the end of the trial. Significant reduction of platelet aggregation was seen in both acute and subacute conditions with complete or almost complete recovery 36 hours after the last dose. It is concluded that ketoprofen affects platelets with readily reversible inhibition of in vitro aggregation and a slight increase of bleeding time.