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Obesity leads to the activation of pro-inflammatory pathways, resulting in a state of low-grade inflammation. Recently, several studies have shown that the exposure to lipopolysaccharide (LPS) could initiate and maintain a chronic state of low-grade inflammation in obese people. As the daily intake of food additives has increased substantially, the aim of the present study was to investigate a potential influence of food additives on the release of leptin, IL-6 and nitrite in the presence of LPS in murine adipocytes. Leptin, IL-6 and nitrite concentrations were analysed in the supernatants of murine 3T3-L1 adipocytes after co-incubation with LPS and the food preservatives, sodium sulphite (SS), sodium benzoate (SB) and the spice and colourant, curcumin, for 24 h. In addition, the kinetics of leptin secretion was analysed. A significant and dose-dependent decrease in leptin was observed after incubating the cells with SB and curcumin for 12 and 24 h, whereas SS decreased leptin concentrations after 24 h of treatment. Moreover, SS increased, while curcumin decreased LPS-stimulated secretion of IL-6, whereas SB had no such effect. None of the compounds that were investigated influenced nitrite production. The food additives SS, SB and curcumin affect the leptin release after co-incubation with LPS from cultured adipocytes in a dose- and time-dependent manner. Decreased leptin release during the consumption of nutrition-derived food additives could decrease the amount of circulating leptin to which the central nervous system is exposed and may therefore contribute to an obesogenic environment.

Objective HDL modifying effects of cholesteryl ester transfer protein (CETP) and hepatic lipase (LIPC) depend in part on each other. We studied associations of CETP -Taq1B and -514C>T- LIPC polymorphisms with hepatic mRNA levels, and their combined effects on plasma lipids and carotid atherosclerosis. Methods We genotyped the CETP -Taq1B and the -514C>T- LIPC polymorphisms in 67 obese women in whom hepatic CETP and LIPC transcript levels were determined as well as in 1549 participants of the Salzburg Atherosclerosis Prevention Program in Subjects at High Individual Risk (SAPHIR). Carotid atherosclerosis was assessed by intima-media thickness and extent of plaques (B-score) of the carotid arteries. Results In obese women, CETP -Taq1B and -514C>T- LIPC variant alleles were associated with reduced hepatic levels of CETP and LIPC mRNA, respectively. The CETP and LIPC polymorphisms accounted for 12.9 and 14.4% of the variability in respective transcripts. In the SAPHIR population, CETP -Taq1B showed independent effects on LDL diameter, HDL and LDL cholesterol, apolipoproteins AI and B and cholesterol/HDL cholesterol, while -514C>T- LIPC revealed independent effects on HDL cholesterol and apolipoprotein AI. The two polymorphisms displayed interactions at the level of HDL cholesterol. Compared to subjects carrying wild-type alleles at both loci, subjects homozygous for the CETP wild-type allele, but heterozygous for the LIPC polymorphism and subjects heterozygous for the CETP polymorphism, but homozygous for the LIPC wild-type allele showed an increased risk of carotid atherosclerosis (both P Conclusions CETP and LIPC polymorphisms influence the respective hepatic transcript levels, demonstrate interactions on HDL cholesterol and suggest that imbalances between CETP and LIPC activities may modulate the risk of carotid atherosclerosis.

ObjectiveTo investigate low-density lipoprotein receptor-related protein 1b (LRP1b) expression in human tissues and to identify circulating ligands of LRP1b.Methods and resultsUsing two independent RT-PCR assays, LRP1b mRNA was detected in human brain, thyroid gland, skeletal muscle, and to a lesser amount in testis but absent in other tissues, including heart, kidney, liver, lung, and placenta. Circulating ligands were purified from human plasma by affinity chromatography using FLAG-tagged recombinant LRP1b ectodomains and identified by mass spectrometry. Using this technique, several potential ligands (fibrinogen, clusterin, vitronectin, histidine rich glycoprotein, serum amyloid P-component, and immunoglobulins) were identified. Direct binding of LRP1b ectodomains to fibrinogen was verified by co-immunoprecipitation. ApoE – carrying lipoproteins were shown to bind to LRP1b ectodomains in a lipoprotein binding assay. Furthermore, binding as well as internalization of very low density lipoproteins by cells expressing an LRP1b minireceptor was demonstrated.DiscussionLRP1b expression in humans appears to be confined to few tissues, which could point out to specialized functions of LRP1b in certain organs. Most of the newly identified LRP1b ligands are well-known factors in blood coagulation and lipoprotein metabolism, suggesting a possible role of LRP1b in atherosclerosis.

We established a murine model of phosphate nephropathy with secondary hyperparathyroidism. db/db mice, which develop obesity and type 2 diabetes mellitus, were uninephrectomized at the age of 6 weeks and were fed either standard chow or a phosphorus-rich diet during the next 8 weeks. Thereafter, renal cryosections showed abundant tubular casts with a strong histochemical von Kossa reaction in all db/db mice on the phosphorus-rich diet but none in the controls. X-ray diffraction and Raman spectroscopy proved that these tubular casts consist mostly of hydroxyapatite Ca 5 (PO 4 ) 3 (OH). These intraluminal precipitations were located in distal tubuli and collecting ducts and were associated with degenerative tubular changes and peritubular infiltration of T cells and macrophages. In line, kidneys of db/db mice on the phosphorus-rich diet displayed significantly increased mRNA expression of the T H 1 cytokines interferon γ, IL-6, and tumor necrosis factor α. In addition, mice developed signs of secondary hyperparathyroidism as shown by elevated serum phosphate, decreased serum calcium, and increased parathyroid hormone, osteopontin, and fibroblast growth factor 23 levels. db/db mice on the phosphorus-rich diet also presented with significantly lower body weight, lower homeostasis model assessment of insulin resistance index, and hypertrophic cardiomyopathy. Thus, we provide a murine model of phosphate nephropathy and secondary hyperparathyroidism, which can be used for future pharmacologic and pathophysiologic studies to analyze the effect of hyperphosphatemia on renal, metabolic, and cardiovascular phenotypes.

Eur J Clin Invest 2011; 41 (9): 937–942 Abstract Background Cumulating evidence suggests that the broadly acting neurotrophic pigment epithelium-derived factor is associated with visceral adiposity, the metabolic syndrome, diabetes and exerts beneficial effects on atherosclerosis. To further elucidate the relationship between pigment epithelium-derived factor and metabolic perturbations characteristic of obesity, we examined the effect of pronounced weight loss on serum levels of pigment epithelium-derived factor. Materials and methods Thirty-six severely obese adults were examined before and 18 months after bariatric surgery. Abdominal fat distribution was determined by ultrasound, metabolic parameters by standard methods, pro-inflammatory biomarkers and serum pigment epithelium-derived factor levels by enzyme-linked immunosorbent assay. Results Bariatric surgery resulted in a mean body mass index (BMI) reduction of 9·0 ± 5·0 kg m−2 and concomitant improvements in glucose homoeostasis and lipid profile. Pigment epithelium-derived factor serum levels decreased from a median 11·0 μg mL−1 (interquartile range: 3·8) to 9·2 μg mL−1 (interquartile range: 4·5) (P 0·370, P

HINTERGRUND: Ein spital-basiertes Screening Projekt (HSP) in Osterreich dokumentierte eine LDL-C Zielwert-Erreichung von 47% der Hochrisikopatienten (Ziel 100 mg/dl bei ca. 70% der Patienten eine Therapie-Intensivierung, meist durch Wechsel auf ein hochpotentes Statin. Bei LDL-C zwischen 70–100 mg/dl erfolgt jedoch weder bei Hoch- noch bei Hochstrisikopatienten eine Therapie-Intensivierung (< 5%). SCHLUSSFOLGERUNG: Sowohl in der Praxis als auch im Spital in Osterreich besteht, weitgehend parallel zu europaischen Analysen, weiterhin betrachtliches Verbesserungspotential in der Lipidzielwert-Erreichung bei kardiovaskularen Hoch- und Hochstrisikopatienten.

Eur J Clin Invest 2010; 40 (7): 616–622 Abstract Background The impact of cholesteryl ester transfer protein (CETP) in the development of atherosclerosis is a matter for ongoing debate. In this study, we analyse associations of CETP with cardiovascular endpoints in a cohort of patients with stable coronary artery disease (CAD). Design KAROLA is a prospective observational study of patients with CAD and a median follow-up of 8 years (n = 1132). CETP levels were measured using an enzyme-linked immunosorbent assay. Results Cholesteryl ester transfer protein levels were lower in men (P = 0·0016), positively correlated to low-density lipoprotein cholesterol, and inversely correlated to triglyceride levels (P

Background. Matrix metalloproteinases (MMPs) and their specific inhibitors (tissue inhibitor of metalloproteinases [TIMPs]), are involved in adipogenesis, angiogenesis and remodeling of extracellular matrix. MMPs and TIMPs have been shown to be associated with various diseases such as neurological disorders, malignancies and cardiovascular disease. MMPs and TIMPs are thought to play a major role in extensive reorganization of the adipose tissue in obesity. Methods and materials. To test whether significant weight loss alters circulating MMPs and TIMPs, 18 morbidly obese women, who underwent bariatric surgery for weight loss, were investigated before and one year after surgery in a prospective design study. Body composition, glucose and lipid metabolism parameters were determined in all study subjects before and after weight loss. Circulating MMP-2, -3, -7 and TIMP-1, -2 and -4 serum levels were measured using commercially available, enzyme-linked immunoassays. Results. Pronounced weight loss was accompanied by improvements in glucose homeostasis and lipid parameters. In the mean time MMP-2 and MMP-3, as well as TIMP-1, -2 and TIMP-4 concentrations were not affected by significant weight loss, and circulating MMP-7 increased significantly after bariatric surgery, although without reaching the standard levels as determined in 18, lean, healthy women. Conclusion. Our data indicate that reduced MMP-7 levels in obesity might be restored by significant weight loss, suggesting that the reorganization of adipose tissue in obesity might be partially reversible by weight reduction. We hypothesize that increased circulating MMP-7 might indicate enhanced adipocyte differentiation in subjects who had undergone bariatric surgery.

Background We recently showed that aspirin promotes scavenger receptor class-B type I (SR-BI) protein expression in vitro in primary human macrophages and in vivo in resident peritoneal macrophages of mice. Methods We compared SR-BI and CD68 expression in carotid atherosclerotic specimens from endarterectomized patients with ( n =38) or without ( n =19) low-dose aspirin medication (100mg/day) prior to endarterectomy. Results We found no differences concerning expression of CD68, indicating that aspirin did not influence macrophage content within atherosclerotic plaques. However, aspirin increased the expression of SR-BI protein in the analyzed specimens. In human THP-1-derived macrophages, induction of SR-BI protein by aspirin was abrogated by concomitant pharmacological inhibition of nuclear factor-kappa B (NF-κB). In in vitro experiments employing cultured primary macrophages from NF-κB/p50 KO mice, aspirin was not able to influence SR-BI expression. Additionally, no considerable effects on SR-BI expression were observed in vivo in resident macrophages of NF-κB/p50 KO mice orally treated with low or high doses of aspirin, respectively. Conclusions We suggest that aspirin treatment might lead to enhanced expression of SR-BI in human plaque macrophages and that this effect is dependent on the presence of NF-κB.

Aims: Vascular endothelial growth factor (VEGF) is a potent hypoxia-regulated angiogenic factor. Its soluble receptor soluble (s)Flt-1 binds VEGF with high affinity inhibiting the angiogenic function of VEGF. The role of circulating VEGF in atherosclerosis is unclear. Methods and results: In 909 healthy subjects (511 male, 398 female) from the Salzburg Atherosclerosis Prevention Program in Subjects at High Individual Risk (SAPHIR) we determined fasting plasma VEGF and sFlt-1 concentration, cardiovascular risk factors and carotid atherosclerosis. VEGF levels were lower and sFlt-1 levels higher in men than in women. VEGF and sFlt-1 showed a positive correlation. In the entire population VEGF correlated positively with age, BMI, insulin resistance, white blood cell and platelet count, C-reactive protein (CRP) and carotid intima media thickness (IMT). After adjustment for age, VEGF showed a weak positive correlation with BMI, liver enzymes, CRP and platelet count in males. In females VEGF correlated negatively with LDL-cholesterol and positively with insulin resistance and platelet count. After adjustment for age, no significant correlation with carotid atherosclerosis could be detected. Conclusion: Plasma VEGF and sFlt-1 are only weakly correlated with cardiovascular risk factors, suggesting that circulating VEGF levels do have only a minor impact on the development of atherosclerosis.

Adipocyte fatty acid binding protein (A-FABP) has been suggested to play an important role in fat metabolism linking obesity and the metabolic syndrome. Increasing A-FABP plasma levels were observed during greatest weight loss after bariatric surgery suggesting that A-FABP may indicate changes in fat mass in dynamic situations. As there are no data on weight gain, we investigated the effect of refeeding anorexic patients on body composition and A-FABP plasma levels. Parameters of glucose and lipid metabolism as well as plasma levels of leptin and A-FABP were prospectively assessed in 16 female patients with anorexia nervosa during inpatient weight restoration. Body composition was determined by multifrequency body impedance analysis. After 28 days, fat mass increased from 4.4 ± 2.5 kg at baseline to 5.5 ± 2.2 kg (P

SummaryValproic acid (VPA) is an effective and widely used anticonvulsant, associated with metabolic adverse effects such as weight gain, hyperinsulinemia, hyperleptinemia and hypoadiponectinemia. The aim of this study was to evaluate the influence of VPA and topiramate (TPM) on adiponectin binding receptors, adipoR1 and adipoR2, in human liver cancer cells, HepG2. AdipoR1 but not adipoR2 gene expression was upregulated by VPA treatment. TPM did neither affect adipoR1 nor adipoR2 gene expression. Given the tight association between VPA treatment, metabolic side effects and the adipocytokine-axis, upregulation of adipoR1 possibly represents a favoured and insulin-sensitizing mechanism.

Several members of the neuropeptide family exert chemotactic actions on blood monocytes consistent with neurogenic inflammation. Furthermore, chromogranin A (CgA) containing Alzheimer plaques are characterized by extensive microglia activation and such activation induces neuronal damage. We therefore hypothesized that the catecholamine release inhibitory peptide catestatin (hCgA(352-372)) would induce directed monocyte migration. We demonstrate that catestatin dose-dependently stimulates chemotaxis of human peripheral blood monocytes, exhibiting its maximal effect at a concentration of 1 nM comparable to the established chemoattractant formylated peptide Met-Leu-Phe (fMLP). The naturally occurring catestatin variants differed in their chemotactic property insofar as that the Pro370Leu variant was even more potent than wild type, whereas the Gly364Ser variant was less effective. Specificity of this effect was shown by inhibition of catestatin-induced chemotaxis by a specific neutralizing antibody. In addition, catestatin mediated effect was blocked by dimethylsphingosine and treatment with endothelial differentiation gene (Edg)-1 and Edg-3 antisense RNA as well as by incubation with pertussis toxin and genistein indicating involvement of tyrosine kinase receptor-, G-protein- and sphingosine-1-phosphate signaling. Catestatin also stimulated Akt- and extracellular signal related kinase (ERK)-phosphorylation and catestatin-induced chemotaxis was blocked by blockers of phosphoinositide-3 (PI-3) kinase and nitric oxide as well as by inhibition of the mitogen-activated protein kinases (MAPK) system indicating involvement of these signal transduction pathways. In summary, our data indicate that catestatin induces monocyte chemotaxis by activation of a variety of signal transduction pathways suggesting a role of this peptide as an inflammatory cytokine.

The metabolic syndrome is associated with low high-density lipoprotein-cholesterol (HDL-C) and decreased low-density lipoprotein (LDL) particle size. The Taq1B-polymorphism in the cholesteryl ester-transfer protein (CETP)-gene influences HDL-C, CETP concentration, and LDL-size. We investigated the effect of the Taq1B-polymorphism on the risk of the metabolic syndrome in 1,503 participants (973 men, 530 women) of the Salzburg Atherosclerosis Prevention program in subjects at High Individual Risk study. CETP concentration was determined in a subgroup (n = 486) by an enzyme-linked immunosorbent assay. Prevalence of the metabolic syndrome was 16.7% (18.5% in men, 13.5% in women). The Taq1B-polymorphism influenced significantly CETP concentrations, HDL-C levels, and LDL-size (P < 0.001 for all). The relative risk of the metabolic syndrome was reduced by 32% (odds ratio (OR) 0.68 (95% CI: 0.51-0.89), P = 0.005) in carriers of the B2 variant. This risk reduction persisted after adjustment for age and sex (OR 0.69 (0.53-0.92), P = 0.01) and after further adjustment for body mass index, waist-to-hip ratio, blood pressure, insulin resistance (IR), HDL-C, and triglycerides (TGs) (OR 0.43 (0.26-0.72), P = 0.001). Furthermore, the risk reduction was more pronounced in men than in women. We conclude that CETP plays an important role in the metabolic syndrome, possibly involving novel functions of CETP.

A prospective study compared the perinatal morbidity of 141 normal pregnancies (group I) with that of 108 pregnancies in whom gestational diabetes had been treated early (group II) and 35 with unsatisfactorily treated gestational diabetes (group III). The therapeutic goal in gestational diabetes was to have a postprandial blood-glucose level of less than 130 mg/100 ml. If this was not achievable through diet alone, insulin was injected once daily. Neonatal macrosomia, dystrophy, acidosis, hyperbilirubinaemia, hypoglycaemia and hypocalcaemia had a normal incidence in group II, but in group III macrosomia was twice as frequent as in group II (P less than 0.02), and acidosis (pH less than 7.20) twice as frequent (P less than 0.05). The results indicate that strict metabolic control in gestational pregnancy will achieve a normal rate of perinatal morbidity.

Background Weight loss induced by bariatric surgery is an effective method to reverse obesity and comorbidities. The aim of this prospective weight loss study was to investigate changes of body fat distribution in relation to adiponectin and its isoforms and further to investigate the influence of both body fat distribution and adiponectin on the degree of liver steatosis. Design Fifteen severely obese female patients (body mass index 43·1 ± 4·1, mean age 34·5 ± 8·6 years) were examined before and after surgical treatment. Grading of fatty liver disease and the subcutaneous and visceral fat diameters were determined by abdominal ultrasonography. Metabolic parameters were determined using standard methods; serum total adiponectin and its isoforms were detected by enzyme immuno assay (EIA). Results Mean weight loss was 28·3 kg, which was mostly due to a loss in fat mass, accompanied by an increase in total adiponectin and the high molecular weight (HMW) adiponectin isoform. Visceral adipose tissue (VAT) diameter was highly correlated with liver steatosis, even more strongly than the parameters of liver function. In addition, liver steatosis correlated negatively with HMW adiponectin and binary logistic regression revealed that changes in fat mass, HMW adiponectin and alanine aminotransferase (ALT) were the best predictors for changes in the degree of hepatic steatosis. Conclusions Our results suggest that circulating HMW adiponectin is associated with both VAT and liver steatosis. In summary, the major findings were that the VAT diameter is highly correlated with liver steatosis, even stronger than the parameters of liver function and the association of HMW adiponectin with liver steatosis was better than with total adiponectin.

Background. Ectonucleotide pyrophosphatase/ phosphodiesterase-1 (ENPP1) generates inorganic pyrophosphate, a solute that serves as an essential physiological inhibitor of calcification. Inactivating mutations of ENPP1 are associated with generalized arterial calcification of infancy. We hypothesized the ENPP1 K121Q variant to be associated with increased vascular calcification in patients with end-stage renal failure. Subjects and methods. We recruited 79 patients with end-stage renal failure undergoing dialysis treatment and genotyped them for the ENPP1 K121Q polymorphism. Next, we matched to each patient with ENPP1 121KQ genotype (n ¼ 15) a respective control with ENPP1 121KK genotype by gender, age, diabetes and duration of dialysis treatment. The matching ratio was 1 : 1. Severity of coronary calcification was quantified by computed tomography, and aortic stiffness was measured by pulse-wave analysis. Results. Patients with ENPP1 121KQ genotype had a significantly higher coronary calcium score (1385 vs 94; n ¼ 30; P ¼ 0.033), and also a higher aortic pulsewave velocity when compared to matched controls with ENPP1 121KK genotype (13.69 m/s vs 9.37 m/s; P ¼ 0.003). Conclusions. Taken together, our study suggests a potential role of the ENPP1 K121Q polymorphism in arterial calcification of patients with end-stage renal failure. Patients heterozygous for the ENPP1 K121Q polymorphism have higher coronary calcification scores and increased aortic stiffness, and may benefit from more intense treatment in order to prevent progression of arterial calcification.

Genetic variations of the scavenger receptor class B type I (SR-BI) have been demonstrated to be associated with plasma lipid parameters, anthropomorphic parameters, and coronary artery disease. We determined the frequency of 3 single-nucleotide polymorphisms within the SR-BI gene (SCARB1) in 354 patients with peripheral arterial disease (PAD) and 354 controls matched for age, sex, and diabetes and related to lipids and disease state, that is, PAD. SCARB1 combined genotype exon 1/intron 5/exon 8 were found to be associated with plasma total and low-density lipoprotein cholesterol levels, respectively. In terms of disease, a significant risk for PAD was observed in female subjects carrying the common allele of exon 8 (odds ratio, 2.623; 95% confidence interval, 1.321-5.208; P = .003). The variant allele of intron 5 was found to be a risk factor for PAD in men (odds ratio, 2.182; 95% confidence interval, 1.288-3.698; P = .005). Furthermore, the SCARB1 combined genotype intron 5/exon 8 proved predictive for PAD in the whole population (P = .006), which remained significant after correction for traditional risk factors. In conclusion, in the present study population, SCARB1 polymorphisms not only show associations with plasma levels of total and low-density lipoprotein cholesterol, respectively, but also with the risk for PAD.

Objective: Adiponectin is an adipocytokine secreted into circulation in three isoforms. The aim of the study was to investigate changes of adiponectin isoforms during profound weight loss and its relation to anthropomorphometric and metabolic parameters. Research Methods and Procedures: Thirteen severely obese female subjects were examined before and 1 year after surgical treatment. Total adiponectin was determined by radioimmunosorbent assay, and oligomer composition was detected by nondenaturing Western blot. Results: BMI decreased substantially (p < 0.001), which was associated with an increase of total adiponectin from 12.9 ± 5.9 to 14.3 ± 6.1 μg/mL (p = 0.055). Medium molecular weight (MMW) adiponectin increased from 7.5 ± 3.6 to 9.1 ± 4.1 μg/mL (p = 0.009), whereas high (HMW) and low molecular weight adiponectin remained unchanged. Δ values of total adiponectin correlated significantly with Δ values of anthropometric parameters. Similar correlations were found for Δ values of MMW (Δ weight: r2 = 0.4132, p = 0.0178; Δ BMI: r2 = 0.3319, p = 0.0393; Δ fat mass: r2 = 0.5202, p = 0.0054). Discussion: Thus, profound weight loss was associated with an increase in total adiponectin, which was mainly and consistently caused by increases in MMW adiponectin (p = 0.009). These changes result in a shift from low molecular weight to MMW and HMW adiponectin isoforms, which may be related to improvements in both anthropometric and metabolic parameters.

In the present study, we investigated the mechanisms by which resistin (100 nM, 1 h) affects glycogen synthesis in L6 skeletal muscle cells. The activity of glycogen synthase, the major enzyme in glycogen synthesis, is determined by both its covalent phosphorylation and allostery through intracellular glucose-6-phosphate. Covalent phosphorylation of glycogen synthase was not altered by resistin and, accordingly, phosphorylation of GSK-3α/β and Akt remained unchanged. The rate of glucose-6-phosphate formation, however, was decreased by resistin both in the absence and presence of insulin; in the absence of insulin, resistin decreased glucose-6-phosphate formation by reducing hexokinase type I activity without affecting glucose uptake; by contrast, in the presence of insulin, resistin decreased glucose-6-phosphate formation by reducing the Vmax of glucose uptake without changing hexokinase type I activity. In conclusion, short-term resistin incubation impairs glycogen synthesis by reducing the rate of glucose-6-phosphate formation involving, however, differential mechanisms in basal and insulin-stimulated states.

Objective. The B1B1 variant of the cholesteryl ester transfer protein (CETP) TaqIB polymorphism and high plasma CETP concentrations are associated with favourable angiographic outcomes in pravastatin-treated patients suffering from coronary artery disease (CAD). The purpose of the present study was to test whether CETP TaqIB genotypes and/or plasma CETP concentrations at baseline also predict clinical end-points in patients with CAD. Design. Prospective longitudinal observational study. Setting. Primary care doctors (n = 88) and hospitals (n = 7) in Austria. Subjects. A total of 1620 men and women with preexisting CAD were recruited and plasma lipids were determined at study entry. 1389 hypercholesterolaemic patients were included and 1002 patients completed the follow-up. Interventions. In all patients treatment with pravastatin was started and patients were followed up for 2 years. Main outcome measures. Cardiovascular events. Results. One hundred patients suffered at least one cardiovascular event. We observed significantly more events in patients within the lowest compared with the highest quartile of plasma CETP concentrations (odds ratio 3.20, CI95 1.65–6.23; P = 0.001, adjusted for known risk factors of CAD). No significantly different numbers of cardiovascular events were found between CETP TaqIB genotypes. Conclusions. Plasma CETP concentrations, but not CETP TaqIB genotypes, predict cardiovascular events in patients with CAD treated with pravastatin. Despite higher LDL cholesterol concentrations, high plasma CETP concentrations at baseline are associated with fewer cardiovascular events compared with low plasma CETP concentrations in CAD patients treated with pravastatin.

Recombinant adenoviral vectors encoding human HDL-cholesterol receptor SR-BI (Ad/hSR-BI) or beta-galactosidase (Ad/lacZ), respectively, were purified using a Source15 Q anion-exchange (AEX) column and quantified using two parallel Taqman Real Time PCR systems with different target sequences. Adenovirus concentrations were ascertained by 260 nm measurements, purity by 260/280 nm ratio and SDS-PAGE. Subsequently, adenoviruses were validated by experimental intravenous application into New Zealand White rabbits. Transgene expression was verified by functional assays determining plasma clearance rate of 3H-HDL-cholesterol, and was not affected by 21-months storage at -80 degrees C. No alterations of liver enzymes and C-reactive protein (CRP) upon Source15 Q adenovirus treatment could be detected, demonstrating biological safety of our protocol.

OBJECTIVE Low high-density lipoprotein cholesterol (HDL-C), hypertriglyceridemia, and small dense-low density lipoprotein (LDL) are key components of metabolic syndrome (MS). Cholesteryl ester transfer protein (CETP) mediates the transfer of triglycerides (TGs) from TG-rich lipoproteins to HDL and LDL particles in exchange for cholesteryl esters, leading to low HDL-C and small dense-LDL. The aim of this study was to investigate the role of CETP in subjects with MS. RESEARCH METHODS AND PROCEDURES In a cross-sectional cohort of 234 middle-aged men and 252 women randomly selected from the Salzburg Atherosclerosis Prevention Program in Subjects at High Individual Risk (SAPHIR) study, MS was diagnosed according to the National Cholesterol Education Program guidelines. CETP mass was determined by enzyme-linked immunosorbent assay and LDL size-by-gradient polyacrylamide gel electrophoresis. RESULTS Men and women with MS had lower HDL-C (45 +/- 7 vs. 58 +/- 13 and 48 +/- 10 vs. 71 +/- 14 mg/dL for men and women, respectively; p < 0.001 for all) and higher TG levels (222 +/- 71 vs. 98 +/- 54 and 167 +/- 67 vs. 90 +/- 35 mg/dL for men and women, respectively; p < 0.001 for all) than healthy subjects. LDL size was lower in subjects with MS (256 +/- 11 A vs. 267 +/- 11 A and 262 +/- 10 A vs. 273 +/- 8 A for men and women, respectively; p < 0.001 for all). CETP mass was higher in men with MS (1.87 +/- 0.78 vs. 1.40 +/- 0.65 mug/mL; p < 0.001) but not in women (1.74 +/- 0.79 vs. 1.62 +/- 0.62 mug/mL). CETP mass correlated inversely with LDL size in both men and women (r = -0.19, p < 0.01 and r = -0.13, p < 0.05 in men and women, respectively). DISCUSSION MS is associated with increased CETP mass in men. Increased CETP mass may be responsible for reduced HDL-C and reduced LDL particle diameter in MS.

Objective Weight gain is a common side effect of psychotropic medications. Mirtazapine, a widely used antidepressant, induces adverse metabolic effects such as an increase in body weight. The aim of this study was to investigate the influence of mirtazapine treatment on body weight, body fat mass, glucose metabolism, lipoprotein profile, and leptin and its soluble receptor in a prospective, controlled study design. Method Seven women who met the ICD-10 diagnostic criteria for a depressive episode (ICD-10: F31-F33) were assigned to monotherapy with mirtazapine and observed for a 6-week period. Seven mentally and physically healthy female volunteers matched for age and body weight served as a control group. Data were collected from November 2002 to December 2003. Results The mean +/- SD body weight increased from 63.6 +/- 13.1 kg to 66.6 +/- 11.9 kg during mirtazapine treatment (p = .027). Fat mass increased in study subjects from 20.9 +/- 9.6 kg to 22.1 +/- 9.3 kg (p = .018). Insulin, glucose, and the homeostasis model assessment (HOMA) index for insulin resistance and lipid parameters remained stable. Leptin concentrations increased from 23.0 +/- 17.1 ng/mL to 40.9 +/- 27.2 ng/mL (p = .018), whereas the soluble leptin receptor concentrations remained stable during mirtazapine treatment. In the control subjects, the investigated parameters remained stable. Between-group analyses of change scores revealed significant differences for body weight (p = .010), body mass index (p = .013), fat mass (p = .035), and leptin (p = .013). Conclusion The antidepressant therapy with mirtazapine was associated with a significant increase in body weight, body fat mass, and leptin concentration. In contrast to other psychotropic medications inducing weight gain, such as some second-generation antipsychotics, mirtazapine treatment did not influence the glucose homeostasis.

BACKGROUND: Adhesion of intratubular leukocytes to proximal tubules in biopsies of patients with rapidly progressive glomerulonephritis and the appearance of leukocytes in the urine in interstitial nephritis suggest interactions between leukocytes and tubular epithelia in renal diseases. The aim of this study was to investigate the effect of cytokines and endotoxin on leukocyte migration through proximal tubular epithelial cells and also to determine the role of the transmembrane adhesion molecules ICAM-1 and CD47 in this process.METHODS: Experiments determined transepithelial migration (TEM) of PMN (polymorphonuclear) leukocytes through monolayers of HK-2. Expression of ICAM-1 and CD47 was assessed via confocal immunofluorescence, FACS analysis and western blotting. The effect of antibodies against ICAM-1 and CD47 on TEM was examined. Furthermore measurements of cytokine release (IL- 6 and IL-8) were performed.RESULTS: Preincubation of HK-2 cells with either TNFalpha or LPS resulted in stimulation of PMN migration through monolayers of HK-2 cells. There was no preferred direction of transmigration. ICAM-1 was expressed by HK-2 cells and expression was increased after 4 h stimulation with TNFalpha or LPS. Application of ICAM-1 antibodies inhibited TEM. CD47 was expressed in both HK-2 cells and PMN. CD47 antibodies inhibited predominantly basolateral-to-apical TEM. HK-2 cells released IL-8 and IL-6 preferably into the apical compartment. Additionally, we showed that fMLP induced transmigration through monolayers of HK-2 cells was associated with significant increased CD47 expression on PMN cell surfaces.CONCLUSIONS: Inflammatory mediators stimulate TEM of PMN through monolayers of HK-2 cells without a clearly discernible preference of direction. Mechanisms involved in TEM stimulated by cytokines or endotoxin appear to be mainly changes in surface receptor densities of HK-2 cells with ICAM-1 and CD47 playing an essential role.

Second-generation antipsychotic agents (SGAs) are increasingly replacing first-generation antipsychotic agents due to their superior activity against the negative symptoms of schizophrenia, decreased extrapyramidal symptoms and better tolerability. However, some SGAs are associated with adverse metabolic effects as significant weight gain, lipid disorders and diabetes mellitus. The pathogenesis of SGA-induced disturbances of glucose homeostasis is unclear. In vivo studies suggest a direct influence of SGAs on peripheral insulin resistance. To this end, we analyzed whether olanzapine might alter glycogen synthesis and the insulin-signaling cascade in L6 myotubes. Glycogen content was diminished in a dose- and time-dependent manner. Within the insulin-signaling cascade IRS-1 tyrosine phosphorylation was induced several fold by insulin and was diminished by preincubation with olanzapine. IRS-1-associated PI3K activity was stimulated by insulin three-fold in L6 myotubes. Olanzapine inhibited insulin-stimulated IRS-1-associated PI3K activity in a dose-dependent manner. Protein mass of AKT, GSK-3 and GS was unaltered, whereas phosphorylation of AKT and GSK-3 was diminished, and pGS was increased. Finally, we compared olanzapine with amisulpride, an SGA clinically not associated with the induction of diabetes mellitus. Glycogen content was diminished in olanzapine-preincubated L6 cells, whereas this effect was not observed under the amisulpride conditions. We conclude that olanzapine impairs glycogen synthesis via inhibition of the classical insulin-signaling cascade and that this inhibitory effect may lead to the induction of insulin resistance in olanzapine-treated patients.

Chronic inflammation is characterized by tissue infiltration with monocytes/macrophages, which possess broad proinflammatory, destructive, and remodeling capacities. Elevated levels of osteoprotegerin, an important regulator of differentiation and activation of osteoclasts that also affects different cells of the immune system, were found in the serum of patients with chronic inflammatory diseases. The study of whether osteoprotegerin affects monocyte locomotion in vitro and the possible mechanisms and pathways involved was investigated using Boyden microchemotaxis chambers and Western blot analyses. Osteoprotegerin significantly stimulated monocyte chemotaxis, whereas preincubation of monocytes with osteoprotegerin inhibited monocyte migration toward optimal concentrations of regulated upon activation normal T cell expressed and secreted, monocyte chemotactic protein -1, and procalcitonin. The effects of osteoprotegerin were abolished by pretreating cells with heparinase I and chondroitinase or antibodies against the ectodomain of syndecan-1. Osteoprotegerin signaling was shown to involve protein kinase C, phosphatidylinositol 3-kinase/Akt, and tyrosine kinase. Data suggest that osteoprotegerin affects monocyte mi-gration and protein kinase C and phosphatidylinositol 3-kinase/Akt activation via syndecan-1. Osteoprotegerin-induced deactivation of monocyte chemotaxis toward different chemokines is due to interaction of osteoprotegerin with heparan sulfate and chondroitin sulfate.

Elevated fasting and postprandial plasma levels of triglyceride-rich lipoproteins (TGRLs), i.e. VLDL/remnants and chylomicrons/remnants, are a characteristic feature of insulin resistance and are considered a consequence of this state. The aim of this study was to investigate whether intact TGRL particles are capable of inducing insulin resistance. We studied the effect of highly purified TGRLs on glycogen synthesis, glycogen synthase activity, glucose uptake, insulin signalling and intramyocellular lipid (IMCL) content using fully differentiated L6 skeletal muscle cells. Incubation with TGRLs diminished insulin-stimulated glycogen synthesis, glycogen synthase activity, glucose uptake and insulin-stimulated phosphorylation of Akt and glycogen synthase kinase 3. Insulin-stimulated tyrosine phosphorylation of IRS-1, and IRS-1- and IRS-2-associated phosphatidylinositol 3-kinase (PI3K) activity were not impaired by TGRLs, suggesting that these steps were not involved in the lipoprotein-induced effects on glucose metabolism. The overall observed effects were time- and dose-dependent and paralleled IMCL accumulation. NEFA concentration in the incubation media did not increase in the presence of TGRLs indicating that the effects observed were solely due to intact lipoprotein particles. Moreover, co-incubation of TGRLs with orlistat, a potent active-site inhibitor of various lipases, did not alter TGRL-induced effects, whereas co-incubation with receptor-associated protein (RAP), which inhibits interaction of TGRL particles with members of the LDL receptor family, reversed the TGRL-induced effects on glycogen synthesis and insulin signalling. Our data suggest that the accumulation of TGRLs in the blood stream of insulin-resistant patients may not only be a consequence of insulin resistance but could also be a cause for it.

Increasing evidence shows the importance of platelet-endothelial cell interactions in the progression of atherosclerosis. Platelets contribute to coronary events both as major components of thrombi and as a triggering factor in inflammation that leads to plaque vulnerability. Recent data suggest that statins, besides their lipid-lowering properties, exert pleiotropic effects that may be beneficial in atherosclerosis. Whether activated platelets influence cyclooxygenase-2 (COX-2) expression in human umbilical vein endothelial cells (HUVEC), the effect of atorvastatin, and possible mechanisms were investigated. COX-2 gene expression in HUVEC was studied using real-time polymerase chain reaction. CD40 ligand surface expression of platelets was tested by fluorescence-activated cell sorting analyses. Activated platelets significantly up-regulated COX-2 gene expression in HUVEC. Co-incubation of platelets with atorvastatin was shown to reverse this up-regulation via reduction of CD40 ligand surface expression on platelets. Data suggest that atorvastatin influences CD40-CD40-ligand-dependent platelet-endothelial interaction and that this influence affects platelet-induced COX-2 expression in HUVEC.

SummaryPlatelet recruitment crucially depends on amplification systems provided by autocrine and paracrine factors such as adenosine diphosphate. In inflammatory states, consumption of coagulation proteins, such as antithrombin aggravates the procoagulant state. In this study, we report that platelets express synde-can-4, an antithrombin-binding cell surface heparan sulphate proteoglycan, whose ligation with antithrombin inhibits activated platelet-dependent superoxide anion release from neut-rophils by the limitation of adenosine diphosphate and adeno-sine triphosphate secretion in activated platelets. Adenosine triphosphate-induced platelet aggregation is reduced after treatment of platelets with antithrombin, which is reversed by blockade of syndecan-4. We further observed that antithrombin limits CD40 ligand expression in adenosine diphosphate-activated platelets and inhibits the shedding of syndecan-4 from activated platelets. Syndecan-4 appears to be directly involved in regulating platelet aggregation as anti-syndecan-4 antibody augments platelet aggregation. We suggest that antithrombin might exert beneficial effects in disseminated intravascular coagulation by reducing platelet activation, observed as inhibited CD40 ligand expression, syndecan-4 shedding, and adenosine diphosphate- and adenosine triphosphate-release from activated platelets with subsequent inhibition of neutrophil respiratory burst. From these data it is concluded that syndecan-4 may play important roles in the regulation of inflammatory effects of platelets.

Circulating monocytic cells may mediate neuroinvasion in transmissible spongiform encephalopathies by transporting prion protein (PrP) from sites of entry to the nervous system. Factors regulating monocyte-derived dendritic cell (DC) functions in neuronal tissue include neurogenic mediators, but their interactions with prion-infected DCs are unknown. Here, we report that neuropeptides regulate the interaction of DCs exposed to PrP 106–126 . Inhibition of neurokinin-1-receptors activation with neurokinin-1-receptor antagonist or antibody attenuates substance P-induced enhancement of DC migration induced by PrP 106–126 and prion-protein-induced DC maturation. Other neuropeptides arrest chemotaxis. Data support a priming role of the neuropeptide substance P in PrP 106–126 -induced migration of DCs involving neurokinin-1-receptors.

Background Increased vascularity of bronchial mucosa is closely related to the expression of angiogenic factors, which contribute to the pathogenesis of diseases such as asthma bronchiale. Objective Here we examine the effects of the angiogenic growth factors angiopoietin 1 and angiopoietin 2 on eosinophil function in vitro and possible involvement of the angiopoietin receptor Tie-2. Methods Eosinophil migration was studied by micropore filter assays. Signaling mechanisms required for angiopoietin-dependent migration were tested by using signaling enzyme blockers. Tie-2 mRNA and receptor expression on the cell surface of eosinophils was demonstrated in RT-PCR and by fluorescence-activated cell sorting analysis. Results Angiopoietin 1 significantly stimulated eosinophil chemotaxis via activation of phosphodiesterase, phosphatidylinositol 3′-kinase, and tyrosine kinases. The effect on eosinophil migration of angiopoietin 1 was reversed by an antibody against the Tie-2 receptor and by angiopoietin 2. Incubation of eosinophils with angiopoietin 1 abolished the chemotactic effects of vascular endothelial growth factor on human eosinophils via the Tie-2 receptor. Finally, Tie-2 expression by human eosinophils was demonstrated on the transcriptional and protein level. Conclusions Data suggest that angiopoietin 1 stimulates directed migration and possibly inhibits vascular endothelial growth factor–induced eosinophil chemotaxis via its Tie-2 receptor, which is expressed by eosinophils. Thus, angiopoietin 1 may play an important role in the modulation of eosinophilic inflammation.

Background—Induction of postnatal vasculogenesis, the mobilization of bone marrow–derived endothelial progenitor cells and incorporation of these cells into sites of blood vessel formation, is a well-known feature of angiogenic cytokines such as vascular endothelial growth factor. We hypothesized that the angiogenic neuropeptide secretoneurin induces this kind of neovascularization.Methods and Results—Secretoneurin induced mobilization of endothelial progenitor cells to sites of vasculogenesis in vivo in the cornea neovascularization assay. Progenitor cells were incorporated into vascular structures or were located adjacent to them. Systemic injection of secretoneurin led to increase of circulating stem cells and endothelial progenitor cells. In vitro secretoneurin induced migration, exerted antiapoptotic effects, and increased the number of these cells. Furthermore, secretoneurin stimulated the mitogen-activated protein kinase system, as shown by phosphorylation of extracellular signal–regulated kinase, and activated the protein kinase B/Akt pathway. Activation of mitogen-activated protein kinase was necessary for increase of cell number and migration, whereas Akt seemed to play a role in migration of endothelial progenitor cells.Conclusions—These data show that the angiogenic neuropeptide secretoneurin stimulates postnatal vasculogenesis by mobilization, migration, and incorporation of endothelial progenitor cells.

Background— Secretoneurin is an abundant neuropeptide of the central, peripheral, and autonomic nervous systems, located in nerve fibers characterized by a close interaction with blood vessels and known to stimulate endothelial cell migration. Methods and Results— We hypothesized that secretoneurin might act as an angiogenic cytokine and tested for these effects in vivo using a mouse cornea neovascularization model and in vitro by assessing capillary tube formation in a matrigel assay. In vivo, secretoneurin-induced neovasculature is characterized by a distinct pattern of arterial and venous vessels of large diameter and length. Immunohistochemical staining for CD-31 revealed endothelial lining of the inner surface of these vessels, and recruitment of α-smooth muscle actin–positive perivascular cells suggests vessel maturation. In vitro, secretoneurin-induced capillary tube formation was dose dependent and specific, confirming that effects of secretoneurin occur directly on endothelial cells. Secretoneurin also stimulated proliferation and exerted antiapoptotic effects on endothelial cells and activated intracellular phosphatidylinositol 3′ kinase/Akt and mitogen-activated protein kinase pathways, as demonstrated by increased phosphorylation of Akt and extracellular signal–regulated kinase. Conclusions— These data show that secretoneurin represents a novel direct angiogenic cytokine and reiterate the coordinated relationship between nervous and vascular systems.

Background: The aim of this study was to compare glucose metabolism in patients with schizophrenia receiving olanzapine with that in control subjects. Method: We conducted a prospective, controlled, open study comparing body weight, fat mass, and indices of insulin resistance/ sensitivity in 10 olanzapine-treated patients with ICD-10 schizophrenia (olanzapine dose range, 7.5-20 mg/day) with those of a group of 10 mentally and physically healthy volunteers. Weight, fat mass, and indices of insulin resistance/sensitivity were assessed over individual 8-week observation periods from November 1997 to October 1999. Results: Fasting serum glucose and fasting serum insulin increased significantly in the olanzapine-treated patients (p = .008 for glucose and p = .006 for insulin). The homeostasis model assessment (HOMA) index for beta cell function did not change significantly in the olanzapine-treated patients, whereas the HOMA index for insulin resistance did increase (p = .006). In the control group, these parameters were stable. A significant increase in body weight (p = .001) and body fat (p = .004) was seen in patients treated with olanzapine, while the control group showed no significant changes. Conclusion: This study indicates that the disturbances in glucose homeostasis during antipsychotic treatment with olanzapine are mainly due to insulin resistance. However, beta cell function remains unaltered in olanzapine-treated patients. We conclude that treatment with some second-generation antipsychotic drugs may lead to insulin resistance.

Objective: In obesity, plasma leptin is high and soluble leptin receptor (sOb-R) levels are low, resulting in a low fraction of bound leptin. The aim of this study was to investigate the influence of insulin resistance (IR) and the metabolic syndrome (MS) on sOb-R concentration and the bound-free ratio of leptin. Research Methods and Procedures: sOb-R, leptin levels, and homeostasis model assessment (HOMA) index for IR were determined in 76 middle-aged obese or overweight men. Results: Concentration of sOb-R and soluble receptor-bound fraction of leptin were lowest in the highest tertile of HOMA-IR. sOb-R and the bound-free ratio of leptin correlated with HOMA-IR, leptin concentration, and waist-to-hip ratio independently of age, BMI, and fat mass. Leptin and waist-to-hip ratio were the sole independent determinants of sOb-R concentration, and BMI, HOMA-IR, and visceral adipose tissue were independent determinants of the bound fractin of leptin. sOb-R concentration and the bound fraction of leptin decreased with increasing numbers of components of the MS, resulting in lower sOb-R concentration and a lower fraction of bound leptin in men with the MS. Discussion: IR and abdominal obesity are associated with low sOb-R concentration and low bound-free ratio of leptin independent of fat mass. Low sOb-R concentration and low bound-free ratio of leptin segregate with components of the MS. We suggest that low sOb-R levels and a low fraction of specifically bound leptin are markers of leptin resistance, which is independently associated with IR and abdominal obesity and may constitute an additional component of the MS.

PURPOSE OF REVIEW: Cholesteryl ester transfer protein facilitates the exchange of neutral lipids between HDL and apolipoprotein B containing lipoproteins, which hold powerful opposing roles as risk factors for coronary artery disease. The question as to whether cholesteryl ester transfer protein promotes or protects from atherosclerosis, however, has not been answered. RECENT FINDINGS: This review considers studies dealing with cholesteryl ester transfer protein variants and their effect on blood lipids in various metabolic and clinical settings. Other studies discussed deal with the association between the transfer protein and cardiovascular disease. Research on the biological activity of the cholesteryl ester transfer protein molecule is described including a first clinical study where pharmacological inhibition of the protein proved to be effective in raising HDL cholesterol. SUMMARY: Data concerning the potential marker role of cholesteryl ester transfer protein, although accumulating, are still inconclusive and, at present, not useful for clinical decision making. Inhibition of the protein was demonstrated to be feasible and appears to be promising.

Objectives We studied associations between iron status and early functional and structural vascular abnormalities in patients with hereditary hemochromatosis (HH). Background Iron may be involved in atherogenesis, and patients bearing a genetic mutation associated with HH are possibly at risk of developing coronary heart disease. Methods We studied the vascular properties of 41 HH patients who had homozygosity for the C282Y mutation, along with 51 age-matched control subjects, by determination of endothelium-dependent dilation (EDD) of the brachial artery and intima-media thickness (IMT) of the carotid artery. Results Male HH patients who were not receiving phlebotomy therapy showed a reduced EDD and increased IMT compared with controls and HH patients receiving therapy. In female HH patients, irrespective of treatment status, vascular parameters were not different from those of controls, and none of these patients had severe iron overload. In HH patients, increased iron load was significantly associated with reduced EDD and increased IMT. Moreover, we found a positive correlation between body iron stores and indicators of oxidative stress. When previously untreated male HH patients were re-investigated after intensive phlebotomy therapy, a significant improvement in EDD was observed (2.6 ± 1.3% before vs. 5.5 ± 2.1% after treatment, p = 0.0015). Conclusions Impaired endothelial function and increased IMT are associated with iron overload, with subsequent induction of oxidative stress, and are not linked to a genetic disability in HH patients. Consequent iron-depletion therapy normalizes endothelial function and may thus reduce the increased risk of cardiovascular events. Female patients may be at a reduced risk, presumably due to continuous iron loss by menstruation.

Heat waves result in excess deaths, excess emergency department visits, and intensive care unit admissions for heat stroke. We describe the clinical features and 3-month outcome of a patient with near-fatal heat stroke, admitted to our intensive care unit in July, 2001. After heavily working for hours at a construction site during a heat wave, the 28-year-old male presented with 41.4 degrees C body temperature and multiorgan failure, consisting of neurological impairment, rhabdomyolysis, acute renal failure, disseminated intravascular coagulation, and acute respiratory distress syndrome (ARDS). In the first week there was no evidence of infection. Treatment included cooling, aggressive volume resuscitation, administration of antithrombin-III concentrates and steroids. The patient survived and recovered normal neurological, renal, respiratory and haematological function, and no disability persisted. This case illustrates survival and complete recovery after multiorgan failure in heat stroke with vigorous intensive care. Treatment with antithrombin and steroids and may well have contributed to the favourable outcome. Correction of reduced antithrombin III levels to supranormal by therapeutic administration of antithrombin III concentrate in disseminated intravascular coagulation of heat stroke was not associated with any bleeding complications.

Objective: Soluble leptin receptor (sOB-R) represents the main binding site for leptin in human blood. The aim of this study was to investigate the relationship between leptin and soluble leptin receptor and the bound/free ratio after pronounced weight reduction. Research Methods and Procedures: A total of 18 morbidly obese women participated in this prospective study. Subjects were examined for fat mass, leptin, and sOB-R concentrations before and 1 year after Swedish adjustable gastric banding. Results: Anthropomorphic measures displayed a significant reduction of body mass index [(42.9 ± 5.6 to 32.9 ± 6.0 kg/m2 (mean ± SD)]. Fat mass decreased from 56.3 ± 9.0 to 33.9 ± 12.5 kg. Plasma leptin concentration decreased from 44.6 ± 18.0 to 20.0 ± 13.1 ng/mL (p < 0.001), whereas the sOB-R levels increased from 11.1 ± 3.6 to 16.6 ± 6.0 U/mL after weight-reducing surgery. Thus, the sOB-R bound fraction of leptin increased from 7% to 33%. Discussion: This work demonstrates a relationship between weight loss, leptin, and sOB-R concentrations in vivo. During weight loss, leptin levels decreased, whereas sOB-R levels and the receptor bound fraction of leptin increased. Thus, sOB-R may negatively regulate free leptin.

BACKGROUND: The purpose of the investigation presented here was to study the effects of insulin therapy in type 2 diabetes mellitus (type 2 DM) not only on glycemic control but also on other components of the metabolic syndrome, including lipid metabolism, blood pressure, and body weight. METHODS: Twelve patients with type 2 DM were studied before and after replacement of sulphonylurea treatment with insulin for 4 months. RESULTS: Insulin therapy resulted in a significant decrease in fasting glucose levels by 26%; glycated hemoglobin decreased by 17% and fructosamine values by 19%. With insulin treatment, fasting plasma triglyceride levels decreased by 28% and total HDL cholesterol and HDL(3) cholesterol increased by 17 and 11%, respectively. Low-density lipoprotein (LDL) cholesterol showed no significant change. The magnitude of postprandial lipemia after ingestion of a standard fatty meal decreased by 38%. Insulin treatment was also accompanied by a 21% increase in lipoprotein lipase (LPL) activity in postheparin plasma and by a 20% increase in cholesteryl ester transfer protein (CETP) activity. Hepatic lipase activity was not changed significantly with insulin. Mean BMI decreased from 28.5+/-4.2 to 28.0+/-3.1 kg/m(2) (P=0.02), which is in keeping with the finding that peripheral insulin levels did not increase and which can be explained by the fact that the insulin regimen was combined with dietary counseling. Accordingly, blood pressure showed no significant change. CONCLUSION: Our study demonstrates that judicious replacement of sulfonylurea treatment with insulin therapy, together with dietary counseling, can result in a simultaneous improvement in the major stigmata of the metabolic syndrome, i.e. a significant improvement in glycemic control and lipid metabolism without unfavorable effects on body weight and blood pressure.

Background: Human adipose tissue expresses and releases proinflammatory cytokines and these measures of chronic inflammation have recently been associated with obesity. Hypothesis: To test whether the proinflammatory state is reversible in subjects undergoing weight loss by surgical measures. Subjects and Methods: Twenty morbidly obese women participated in this prospective study. Subjects were examined for fat mass, high-sensitive C-reactive protein (hs-CRP), interleukin 6 (IL-6) and tumor necrosis factor-alpha (TNF-α) before and 1 y after Swedish adjustable gastric banding. Results: Anthropometric measures displayed a significant reduction of the body mass index (BMI) from 41.6±5.4 to 30.8±6.1 kg/m2 and the fat mass from 53.9±10.3 to 29.8±12.1 kg (mean±s.d.). Hs-CRP levels decreased significantly from 1.33±1.21 mg/dl in pre-gastric banding subjects to 0.40±0.61 mg/dl in post-gastric banding subjects, respectively. IL-6 and TNF-α levels did not differ significantly between pre- and post-gastric banding subjects. Conclusions: We speculate that in these patients the marked reduction in C-reactive protein might be beneficial in reducing their cardiovascular risk and is not solely mediated by IL-6 and TNF-α.

AIM: Phospholipid transfer protein (PLTP) and cholesteryl ester transfer protein (CETP) are key enzymes in lipoprotein metabolism facilitating the transfer and exchange of cholesteryl esters, triglycerides and phospholipids between lipoproteins. In the study presented here, we investigated the influence of two hormones-the adipocyte-derived hormone leptin as well as insulin on the hepatic secretion of both, PLTP and CETP. METHODS: PLTP activity and CETP concentration-measured by exogenous substrate assay and enzyme-linked immunosorbent assay-were determined in supernatant of human hepatoma cell line HepG2 after single or combined exposure to leptin and insulin at physiological and supraphysiological concentrations, respectively. Messenger-RNA of PLTP and CETP was quantified by Northern blot analysis. RESULTS: Leptin suppressed PLTP activity and CETP-concentration by up to 33% and 23%, respectively. Insulin also suppressed PLTP activity by up to 11% and CETP-concentration by up to 16%. In combination, the two hormones had additive suppressive effects for both, PLTP activity and CETP-concentration. Northern blot analysis showed no difference in m-RNA levels after exposure to leptin or insulin. CONCLUSIONS: Leptin and insulin, both known to increase with body fat mass, suppress production of PLTP and CETP in HepG2 cells. When extrapolated to the in vivo situation, this suppressive effect may constitute a mechanism counteracting the potentially harmful action of lipid transfer proteins, particularly reduction of HDL-cholesterol, in conditions frequently associated with increased plasma triglyceride levels such as obesity and insulin resistance.

Cholesteryl ester transfer protein (CETP) mediates the exchange of neutral lipids among plasma lipoproteins and is expressed predominantly in liver and intestine. In band shift assays employing nuclear extracts of HepG2 cells we identified C/EBPbeta as the predominant C/EBP isoform involved in binding to the C/EBP consensus sequence within the 5' upstream region of the CETP gene. This was demonstrated by supershift experiments using antibodies specific for C/EBPalpha, C/EBPbeta and C/EBPdelta and an oligonucleotide containing a single point mutation (CAAT--CTAT) in this site. Expression of a CETP promoter-fragment/luciferase construct in transiently transfected HepG2 and CaCo-2 cells and enhancement of promoter activity by co-transfection with human C/EBPalpha in HepG2 cells could be influenced neither by the mutation in the consensus sequence nor by elimination of this site together with a second potential binding site for C/EBP. Furthermore, transfection of HepG2 with human C/EBPalpha did not influence the synthesis of CETP by these cells. Our results indicate that the expression of C/EBP in HepG2 cells is not able (1) to influence specifically the expression of a transfected CETP promoter dependent reporter through binding to C/EBP sites in the promoter region and (2) to significantly enhance expression of the endogenous CETP gene.

Abstract A patient is described who exhibited, despite excessively high postprandial triglyceride levels, high levels of HDL cholesterol. Measurement of CETP activity and mass in the patient’s plasma showed values of less than 5% and 2%, respectively, of a normolipidemic plasma pool. The CETP cDNA of the patient exhibited a mutation (T → G), turning codon 57 (TAT) of exon 2 into a stop codon (TAG) and abolishing a, Xcm I restriction site. Digestion of directly amplified CETP cDNA from the patient with Xcm I indicated the exclusive presence of CETP cDNA containing the mutation. Analysis of the corresponding region of the CETP gene indicated the patient to be heterozygous for the nonsense mutation at codon 57, a finding that can only be explained by the presence of a null allele in addition to the allele with the nonsense mutation. The combination of TG intolerance of uncertain cause, together with CETP deficiency due to a novel mutation, produced the paradoxical constellation—high levels of HDL cholesterol (172 mg/dL) associated with a high postprandial lipemia of 1460 mg triglycerides/dL.8 hours—and provided further insight into the role of CETP as mediator between pools of triglycerides and cholesteryl esters in plasma.

Paroxysmal nocturnal haemoglominuria (PNH) is an acquired clonal stem cell disorder resulting in insufficient and defective haematopoesis associated frequently with aplastic anaemia (AA). A deficiency of the glycosyl phosphatidylinositol (GPI)-anchored complement activation regulatory proteins CD55 and CD59 is responsible for an increased sensitivity of, erythrocytes to complement attack leading to chronic intravascular haemolysis with haemoglob inuria. In this study we investigated the effects of complement activation caused by anti-thymocyte globulin (ATG) treatment on the PNH clone in a patient affected with the PNH/AA-syndrome. Fluid phase complement components C3, C4, C6 and terminal complement complex (TCC) were assayed by ELISA. CD55, CD59 and cell-associated TCC were monitored by flow cytometry. ATG treatment resulted in profound systemic complement activation which led to a decrease in the levels of native C3 and C4 to 65% and 40%, respectively, of the original levels on day 5 and of C6 and TCC to 61% and 23%, respectively, on day 10. A return to pre-treatment levels was observed for C3 by day 15, for C6 by day 30 and for C4 by day 90. Flow cytometry revealed that the deficiency in the GPI-anchored protein was restricted to granulocytes, while lymphocytes remained unaffected. Cell-bound TCC increased by 1.67-fold and 2.37-fold on day 5 and day 10, respectively, decreasing to 1.40-fold and 1.30-fold on day 15 and day 30, respectively. The percentage of PNH granulocytes as identified by the absence of the CD55- and CD59-antigens exhibited a temporary decrease from 72% on day 0 to 65% on day 5 and 59% on day 10 and returned thereafter to the original percentage of 70% by day 15 and exceeding this level to 76% on day 30 and 79% on day 90. We report profound activation of the classical pathway of the complement cascade and the terminal complement complex by the globulin leading to a transient decrease of the PNH clone, presumably due to subsequent lysis of the PNH cells devoid of complement regulatory proteins.

To characterize the mechanisms of complement activation by human immunodeficiency virus type 1 (HIV-1)-infected cells, Cl-4 cells stably expressing the envelope glycoproteins of HIV-1 and the parent African green monkey cell line CV-1 were tested for C1q binding and complement activation. While the parent cell line CV-1 only showed a weak spontaneous activation of the alternative pathway, Cl-4 cells additionally triggered the classical pathway of complement activation independent of anti-HIV antibodies by direct C1q binding. Earlier studies had shown different complement activating potential of cells infected with various HIV isolates. Recombinant soluble CD4-induced shedding of gp120 from the surface of HIV-1-infected cells converted a weak activator isolate (MVP-899) into a strong complement activator. The increase in complement activation was paralleled by the concomitant unmasking of a previously hidden gp41 epitope comprising the major complement-activating domain of gp41 (aa. 601-613). Our results strongly suggest that the transmembrane protein gp41 induces the activation of complement on the surface of infected cells as has been described previously for purified HIV-1 virions. Furthermore, we present evidence that the different potential of HIV isolates to activate the complement system on the cell surface is caused by different degrees of spontaneous gp120 shedding by various HIV isolates.