Cigarette smoking represses expression of cytokine IL-12 and its regulator miR-21-An observational study in patients with coronary artery disease.

RATIONALE: The heterodimer IL-12 is an inducer of Th1 responses and stimulates INFÆ´ production. Micro-RNA-21 (miR-21) is described as a key regulator of the pro-inflammatory response and has IL-12p35 mRNA as one of its main targets. The IL-12p40 1188A/C genetic variant located in 3'untranslated region (UTR), thus environmentally exposed, has further been reported to modify IL-12 levels. We have previously reported on the lowering effect of cigarette smoke on circulating IL-12 in patients with coronary artery disease (CAD). OBJECTIVES: To explore if cigarette smoking affects IL-12p35, IL-12p40, INFÆ´ and miR-21 gene-expression and further modulates any effect of the IL-12p40 polymorphism on circulating IL-12 levels. METHODS AND RESULTS: The IL-12p40 1188A/C polymorphism was analyzed in 1001 stable CAD patients, of which 330 subjects were included for IL-12p35, IL-12p40 and INFÆ´ gene-expression analyses in circulating leukocytes and 200 were further selected for plasma miR-21 analysis. Smoking associated with lower expression of miR-21 and its target IL-12p35 mRNA (adjusted p<0.05, both) whereas the influence on INFÆ´ expression tended to be high-dose reliant (p = 0.057). The IL-12p40 CC genotype associated with elevated circulating IL-12 levels, however, when stratified according to smoking, only in the non-smoking group (adjusted p < 0.05). Although the markers were mainly downregulated in current smokers, their inter-correlations were potentiated. CONCLUSION: Smoking associated with reduced miR-21 gene-repression and the results can therefore not explain the previously observed reduction in circulating IL-12. Smoking attenuated the IL-12 pro-inflammatory axis in which the investigated IL-12p40 genetic variant may have different clinical impact in smokers vs non-smokers.

Circulating lipopolysaccharides in the blood from "bioprotein" production workers.

BACKGROUND: Workers producing bacterial single-cell protein (BSCP), "bioprotein," are exposed to organic dust containing high levels of endoxins (lipopolysaccharides, LPS). Workers in this industry have complained of episodes of fever, fatigue, chest tightness, skin dryness and rubor. The aim of the present study was to quantify LPS and inflammatory mediators in plasma among the workers and non-exposed control subjects. METHODS: We included eight non-smoking production workers, aged 32-51 (median 38), and eight non-smoking, non-exposed controls, aged 30-51 (median 39). Airborne and plasma endotoxin concentrations were measured, as well as plasma hsCRP and different cytokines, chemokines and metalloproteinases. RESULTS: The workers who did not use personal respiratory protection were exposed to varying airborne levels of endotoxin, 430 (75-15 000) EU/m3 (median, range). The level of plasma LPS was significantly elevated (p = 0.01) among the workers compared to the non-exposed controls. The workers also had elevated levels of MCP-1 (p = 0.02), MIP-1alpha (p = 0.05) and MMP-3 (p = 0.04). IL-6 and hsCRP were also elevated among the exposed group, but not significantly (p = 0.10 and p = 0.07, respectively). CONCLUSIONS: In this study, we detected LPS in plasma of individuals exposed to high levels of LPS at their workplace. This finding is supported by elevated levels of several inflammatory cytokines among the workers, significantly exceeding that of the non-exposed control group. To the best of our knowledge, this is the first time that plasma LPS, together with increased inflammatory markers in plasma, has been detected in an occupational setting.

Neisseria meningitidis lipopolysaccharides in human pathology.

Neisseria meningitidis causes meningitis, fulminant septicemia or mild meningococcemia attacking mainly children and young adults. Lipopolysaccharides (LPS) consist of a symmetrical hexa-acyl lipid A and a short oligosaccharide chain and are classified in 11 immunotypes. Lipid A is the primary toxic component of N. meningitidis. LPS levels in plasma and cerebrospinal fluid as determined by Limulus amebocyte lysate (LAL) assay are quantitatively closely associated with inflammatory mediators, clinical symptoms, and outcome. Patients with persistent septic shock, multiple organ failure, and severe coagulopathy reveal extraordinarily high levels of LPS in plasma. The cytokine production is compartmentalized to either the circulation or to the subarachnoid space. Mortality related to shock increases from 0% to > 80% with a 10-fold increase of plasma LPS from 10 to 100 endotoxin units/ml. Hemorrhagic skin lesions and thrombosis are caused by up-regulation of tissue factor which induces coagulation, and by inhibition of fibrinolysis by plasminogen activator inhibitor 1 (PAI-1). Effective antibiotic treatment results in a rapid decline of plasma LPS (half-life 1-3 h) and cytokines, and reduced generation of thrombin, and PAI-1. Early antibiotic treatment is mandatory. Three intervention trials to block lipid A have not significantly reduced the mortality of meningococcal septicemia.

Cellular activating properties and morphology of membrane-bound and purified meningococcal lipopolysaccharide.

Neisseria meningitidis, the cause of epidemic meningitis and acute lethal sepsis, synthesizes surplus lipopolysaccharides (LPSs) during growth, which are released as outer membrane vesicles (OMV) or "blebs". Meningococcal disease severity is related to plasma LPS levels. We have compared the biological activities of native outer membrane vesicles (nOMV) to those of purified Nm-LPS (Nm-LPS) and LPS-depleted OMV (dOMV) prepared from N. meningitidis. The LPS content of nOMV was determined spectrophotometrically by quantifying KDO and by silver-stained SDS-PAGE gels. The morphology of the preparations was studied by transmission electron microscopy. The Limulus amoebocyte lysate (LAL) assay was used to quantify LPS in the plasma solutions. The preparations were diluted in endotoxin-free heparin plasma to equal amounts of LPS (w/w) in the range 50-5000 pg/ml. The biological reactivity was tested by: (i) a monocyte target-assay (monocyte purity > or =96%); and (ii) a whole blood model, measuring the secretion of TNF-alpha and IL-6 induction of procoagulant activity in monocytes (PCA). In both models, nOMV induced dose-dependent cell responses (TNF-alpha, IL-6, PCA) similar to purified Nm-LPS, whereas dOMV induced minimal responses. However, LAL activity was significantly higher for nOMV than for purified Nm-LPS and dOMV. The cellular responses of purified Nm-LPS and nOMV were reduced (>95%) by a specific anti-CD14-antibody.

[The effect of doxazosin on blood pressure, lipids, fibrinogen and plasminogen activator inhibitor. A comparative study among smokers and non-smokers with essential hypertension]. / Effekten av doxazosin på blodtrykk, lipider, fibrinogen og plasminogenaktivator-inhibitor. En sammenliknende studie hos røykere og ikke-røykere med essensiell hypertensjon.

Hypertensive cigarette smokers run particularly high risk of coronary heart disease. Doxazosin, which has beneficial effects on haemodynamic factors and lipid metabolism, may be a suitable agent for treating these patients. The effects on blood pressure and metabolic parameters were investigated in a 16-week, open, parallel, comparative study comprising 64 heavy cigarette smokers and 69 non-smokers who received doxazosin after four weeks on placebo. Eight patients (three smokers and five non-smokers) dropped out due to adverse effects. Blood pressure was significantly reduced in both groups, but there was no change in heart rate. Doxazosin induced a decrease in the triglyceride, total cholesterol and LDL-cholesterol levels, and an increase in HDL-cholesterol concentration. Thus, doxazosin has favourable effects on atherogenic factors in smoking hypertensive patients. There was also a significant lowering of plasma fibrinogen levels and plasminogen activator inhibitor (PAI-1) concentration in non-smokers.

Selective alpha 1 inhibition with doxazosin in hypertensive smokers and non-smokers: haemodynamic and metabolic effects.

Hypertensive cigarette smokers have an especially high risk of coronary heart disease. Doxazosin, which has beneficial effects on haemodynamic factors and lipid metabolism, may be suitable for treating these patients. The haemodynamic and metabolic effects of doxazosin were investigated in a 16-week open, parallel, comparative study of 64 heavy cigarette smokers and 69 non-smokers after a 4-week placebo period. Of the 133 patients who entered, six patients (one smoker and five non-smokers) withdrew due to adverse events. Doxazosin significantly reduced blood pressure without reflex tachycardia in both the smokers and the non-smokers. The therapeutic success rates (reduction in sitting diastolic blood pressure to less than or equal to 90 mmHg and greater than or equal to 5 mmHg reduction, or greater than or equal to 10 mmHg reduction from baseline) were similar for the smokers (93.3%) and the non-smokers (92.5%). Doxazosin significantly decreased total cholesterol and low-density lipoprotein (LDL) cholesterol, but increased high-density lipoprotein (HDL) cholesterol and the HDL:total cholesterol ratio in both smokers and non-smokers. Doxazosin corrected the reduction in HDL cholesterol caused by smoking; compared with baseline, doxazosin increased HDL cholesterol by 19% in hypertensive smokers. The beneficial effects of doxazosin on blood pressure and the lipid profile were apparent in the change in the 10-year probability of developing coronary heart disease as calculated by the Framingham equation; the calculated risk of coronary heart disease decreased by 39% in smokers and by 33% in non-smokers. Plasma fibrinogen and plasminogen activator inhibitor, which independently contribute to atherosclerosis, were significantly reduced by doxazosin in the non-smokers but not in the smokers.

Plasminogen activator inhibitor 1 and 2, alpha-2-antiplasmin, plasminogen, and endotoxin levels in systemic meningococcal disease.

We have studied the activation state of the fibrinolytic system in 39 patients with systemic meningococcal disease (SMD). Patients defined as having fulminant septicemia (n = 13) with high (greater than 700 ng/L) levels of endotoxin (LPS) in plasma and severe coagulopathy, had significantly lower functional levels of plasminogen (P less than 0.05) and alpha-2-antiplasmin (P less than 0.01) and higher antigen levels of plasminogen activator inhibitor 1 (PAI-1) (P less than 0.01), and fibrin degradation products (FDP) (P less than 0.01), but not of PAI-2 (P greater than 0.1) as compared with less severely ill patients (meningitis and meningococcemia) (n = 25). A positive correlation existed between the admission (maximum) levels of LPS and PAI-1 (r = 0.86, P less than 0.0001). Decreasing admission levels of platelets were associated with increasing levels of PAI-1 (r = -0.55, P less than 0.001). After initiation of treatment with antibiotics and fresh frozen plasma, the PAI-1 levels declined rapidly. PAI-1 levels greater than 360 micrograms/L on admission predicted the development of a severe septic shock combined with renal impairment correctly in 12 of 13 patients (92%). None of 25 patients without multiple organ failure had PAI-1 levels greater than 260 micrograms/L. PAI-1 levels greater than 1850 micrograms/L were associated with 100% fatality. The results suggest that in the early phase of fulminant meningococcal septicemia an extensive plasmin generation occurs. On admission, however, high levels of PAI-1 seem to inhibit the plasmin generation, and thereby promote DIC.