Michal Karpisek

Serum FGF21 Levels Are Increased in Obesity and Are Independently Associated With the Metabolic Syndrome in Humans

OBJECTIVE— Fibroblast growth factor 21 (FGF21) is a metabolic regulator with multiple beneficial effects on glucose homeostasis and insulin sensitivity in animal models. This study aimed to investigate the relationship between its serum levels and various cardiometabolic parameters in humans. RESEARCH DESIGN AND METHODS— A newly developed immunoassay was used to measure serum FGF21 levels in 232 Chinese subjects recruited from our previous cross-sectional studies. The mRNA expression levels of FGF21 in the liver and adipose tissues were quantified by real-time PCR. RESULTS— Serum FGF21 levels in overweight/obese subjects were significantly higher than in lean individuals. Serum FGF21 correlated positively with adiposity, fasting insulin, and triglycerides but negatively with HDL cholesterol, after adjusting for age and BMI. Logistic regression analysis demonstrated an independent association between serum FGF21 and the metabolic syndrome. Furthermore, the increased risk of the metabolic syndrome associated with high serum FGF21 was over and above the effects of individual components of the metabolic syndrome. Our in vitro study detected a differentiation-dependent expression of FGF21 in 3T3-L1 adipocytes and human adipocytes. In db/db obese mice, FGF21 mRNA expression was markedly increased in both the liver and adipose tissue compared with that in their lean littermates. Furthermore, FGF21 expression in subcutaneous fat correlated well with its circulating concentrations in humans. CONCLUSIONS— FGF21 is a novel adipokine associated with obesity-related metabolic complications in humans. The paradoxical increase of serum FGF21 in obese individuals, which may be explained by a compensatory response or resistance to FGF21, warrants further investigation.

Fibroblast growth factor‐19: Development, analytical characterization and clinical evaluation of a new ELISA test

Objective. Since fibroblast growth factor 19 (FGF‐19) is a potent metabolic regulator that influences glucose and lipid homeostasis, our aim was to develop an ELISA assay for measuring FGF‐19 in human serum and to investigate its concentrations in healthy volunteers and patients suffering from metabolic syndrome. Material and methods. A sandwich ELISA method was developed for quantitative determination of human FGF‐19 in serum samples. Blood pressure, waist circumference, FGF‐21 serum levels, serum cholesterol, triacylglycerols, HDL‐cholesterol, LDL‐cholesterol, insulin, glucose, adiponectin, uric acid, creatinine, hs‐CRP and calculated BMI and Quicki insulin sensitivity index were measured in 153 healthy volunteers and 66 persons with metabolic syndrome. Results. Neither sex nor age influenced FGF‐19 serum concentration in the healthy volunteers. Probands with metabolic syndrome had 65 % lower FGF‐19 serum values than the healthy ones (medians 158.6 versus 242.4 ng/L; p<0.01). FGF‐19 correlated with glucose (r = −0.35, p<0.01), HDL (r = 0.24, p = 0.045), triacylglycerols (r = −0.19, p = 0.05) and with a number of other risk facors for metabolic syndrome (r = −0.28, p = 0.01). When adjusted to the concentrations of triacylglycerols, BMI and glucose, and finally to all data pertinent to FGF‐19 (according to correlation analysis), our data indicate that FGF‐19 is an independent marker of metabolic syndrome. Conclusions. The present study demonstrates the analytical properties of the ELISA FGF‐19 assay and its usefulness when studying the metabolic syndrome. Serum concentrations of FGF‐19 could be new key predictors of metabolic syndrome and thereby even a new negative risk factor of atherosclerosis.

Pigment epithelium-derived factor as a new marker of metabolic syndrome in Caucasian population

Authors present that serum pigment epithelium derived factor (PEDF) is an independent marker of metabolic syndrome in Caucasianpopulation. PEDF was measured with new ELISA sandwich test. J. Clin. Lab. Anal. 24:17–19, 2010.

Cytotoxicity and effects on inflammatory response of modified types of cellulose in macrophage-like THP-1 cells

The cytotoxicity and in vitro effects of six variously modified types of cellulose (OC--oxidized cellulose, NaOC--oxidized cellulose sodium salt, DAC--dialdehyde cellulose, CMC--carboxymethyl cellulose, MFC--microfibrilated cellulose, and MCC--microcrystalline cellulose) on the inflammatory response in macrophage-like THP-1 cells were examined, with special focus on their ability to influence gene expression and the production of TNF-α. The study provides evidence that DAC exerts a marked effect on the induction of TNF-α gene expression and its subsequent production in human macrophages. Thus, the use of DAC for anti-hemorrhagic or wound-healing therapy should be considered carefully with regard to its pro-inflammatory activity. On the contrary, MCC showed significant anti-inflammatory effects in the LPS-induced conditions, which might be beneficial for the treatment of non-healing chronic wounds, e.g., diabetic or venous ulcers.

DETERMINATION OF SERUM VISININ LIKE PROTEIN-1 AND ITS POTENTIAL FOR THE DIAGNOSIS OF BRAIN INJURY DUE TO THE STROKE – A PILOT STUDY

BACKGROUND The current diagnosis of stroke relies on clinical examination by a physician supplemented by various neuroimaging techniques. A single set or multiple sets of blood biomarkers that could be used in acute settings to diagnosis stroke, differentiate between stroke types, and ideally predict an initial/recurring stroke would be extremely valuable. The diagnosis of stroke is currently hampered by delay due to lack of a suitable tool for rapid, accurate and analytically sensitive biomarker - based testing. There is a clear need for further assay development and clinical validation in this area (acute stroke setting) in order to improve patient outcomes and quality of life. Visinin like protein 1 (VILIP-1) is a newly discovered CNS-abundant protein which has shown promise in experimental studies, for early stroke diagnosis. However, to date there is no clinical study that has measured VILIP-1 in sera as a marker of stroke. AIM To develop an assay for the determination of VILIP-1 in human serum, and to investigate its clinical relevance as a marker of ischemic stroke. DESIGN AND METHODS A new sandwich ELISA was developed, introduced and clinically tested. Mean spiking recovery was 98%. The mean recovery for dilution linearity was 93%. The limit of detection of the assay was 0.01 mcg/l; the intraassay and interassay coefficient of variation (CV) were always less than 10%. The study was approved by the Ethics Commission of the Hospital Šternberk, Czech Republic. A total of 17 healthy individuals (9 men and 8 women, age 64.0 ± 13.0) and 16 individuals with ischemic stroke (10 men and 6 women, age 63.0±11.5) were recruited for our study. The criteria of stroke were proposed by the National Czech Standard. All individuals had blood samples drawn, and VILIP-1 analysis and CT and/or MRI were performed. Results. VILIP-1 serum level significantly differentiated healthy subjects from patients with stroke (P<0.01). All individuals with stroke had VILIP-1 serum values higher than > 0.05 mcg/l, healthy had values below this value. The diagnostic efficacy of serum VILIP-1 was very significant (sensitivity 100%, specificity 100% at 0.093 mcg/l VILIP-1 serum values, AUC 1.0 (CI 0.93-1.0, P<0.01), Chi-squared in the frequency table was 33 (P<0.01). CONCLUSION We have introduced a new analytical tool for the study of VILIP-1. Our results support the hypothesis that serum VILIP-1 may be associated with ischemic stroke. The ELISA VILIP-1 assay offers a new research tool for the diagnosis and pathophysiology of stroke and other CNS diseases.

Olanzapine-depot administration induces time-dependent changes in adipose tissue endocrine function in rats.

OBJECTIVE Metabolic adverse effects of atypical antipsychotics (AAP) contribute significantly to increased risk of cardiovascular morbidity and mortality in patients suffering from schizophrenia. Extensive preclinical research has addressed this issue over the past years, though mechanisms underlying these adverse effects of AAP are still not understood completely. Recently, attention is drawn towards the role of adipose tissue metabolism and neurohormonal regulations. METHODS The aim of this study was to evaluate the time-dependent effects of olanzapine depot administration at clinically relevant dosing on the regulation of energy homeostasis, glucose and lipid metabolism, gastrointestinal and adipose tissue-derived hormones involved in energy balance regulations in female Sprague-Dawley rats. The study lasted 8 weeks and the markers were assayed at day 8, 15, 29, 43 and 57. RESULTS The results indicate that in the absence of hyperphagia, olanzapine chronic exposure induced weight gain from the beginning of the study. In the later time-point, increased adiposity was also observed. In the initial phase of the study, lipid profile was altered by an early increase in triglyceride level and highly elevated leptin level was observed. Clear bi-phasic time-dependent effect of olanzapine on leptin serum concentration was demonstrated. Olanzapine treatment did not lead to changes in serum levels of ghrelin, FGF-21 and pro-inflammatory markers IL-1a, IL-6 and TNF-α at any time-point of the study. CONCLUSION This study provides data suggesting early alteration in adipose tissue endocrine function as a factor involved in mechanisms underlying metabolic adverse effects of antipsychotics.

Tobacco smoking and cytokine levels in human epicardial adipose tissue: Impact of smoking cessation

BACKGROUND & AIMS Epicardial adipose tissue (EAT) is a source of a number of cytokines which could act in the pathogenesis of coronary artery disease (CAD). The potential relationship between known cardiovascular risk factors, such as smoking, dyslipidaemia or diabetes mellitus and EAT humoral signalling, has not been fully elucidated. Therefore, we designed and conducted a cross-sectional study to determine whether selected cardiovascular risk factors are linked to levels of cytokines in epicardial and subcutaneous adipose tissue (SAT). METHODS Samples of SAT and EAT were collected from consecutive patients undergoing scheduled cardiac surgery. Tissue concentrations of tumour necrosis factor-ɑ (TNF-α), interleukin-6 (IL-6), adipocyte fatty acid-binding protein, leptin, and adiponectin were determined by ELISA. RESULTS We enrolled 140 patients. TNF-α and IL-6 concentrations in EAT and SAT were significantly higher in current smokers (CS) than in never smokers (NS) and former smokers (FS). There were no differences between FS and NS. No other clinical variables were associated with cytokine concentrations in a regression analysis. CONCLUSIONS Smoking was independently associated with higher TNF-α and IL-6 concentrations in EAT and SAT. A novel observation that pro-inflammatory cytokines are elevated in EAT in smokers could contribute to identify potential mechanisms involved in the pathogenesis of adverse effects of tobacco smoking. There were no differences between EAT cytokine production in NS and FS, which support the importance of smoking cessation for cardiovascular risk reduction.

Impact of cardiopulmonary bypass surgery on cytokines in epicardial adipose tissue: comparison with subcutaneous fat

Background: Cardiac surgery and cardiopulmonary bypass (CPB) have been shown to stimulate a systemic inflammatory response which has been associated with adverse postoperative outcomes. Adipose tissue, both epicardial (EAT) and subcutaneous (SAT), is a known source of inflammatory cytokines, but its role in the pathophysiology of surgery- and CPB-induced systemic inflammatory response has not been fully elucidated. Therefore, we conducted a study to establish levels of selected cytokines in EAT and SAT prior to and after surgery with CPB. Methods: Adipose tissue samples were obtained from patients undergoing planned cardiac surgery on CPB. Samples from EAT and SAT were collected before and immediately after CPB. Levels of tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), adipocyte fatty acid-binding protein (AFABP), leptin and adiponectin were determined by ELISA, which were adjusted for a total concentration of proteins in the individual samples. Results: Samples from 77 patients (mean age 67.68 ± 11.5 years) were obtained and analysed. Leptin, adiponectin, TNF-α and AFABP were shown to decrease their concentrations statistically significantly in the EAT after CPB while no statistically significant drop was observed in the SAT. On the contrary, IL-6 showed only a slight and statistically insignificant decrease in the EAT after CPB and it was in the SAT where a statistically significant drop was observed. Discussion: One of the most relevant findings of this study was the marked decrease in EAT levels of TNF-α, AFABP, leptin and adiponectin after the CPB termination. Our results suggest that EAT might serve as a pool of cytokines which are released into the circulation in reaction to surgery with CPB. Should these novel findings be confirmed, new strategies to assess and possibly reduce EAT contribution on adverse outcomes of cardiac surgery may be developed.

Aripiprazole-induced adverse metabolic alterations in polyI:C neurodevelopmental model of schizophrenia in rats

&NA; Schizophrenia appears to be linked to higher incidence of metabolic syndrome even in the absence of antipsychotic treatment. Atypical antipsychotics substantially differ in their propensity to induce metabolic alterations. Aripiprazole is considered to represent an antipsychotic drug with low risk of metabolic syndrome development. The aim of this study was to evaluate metabolic phenotype of neurodevelopmental polyI:C rat model and assess metabolic effects of chronic aripiprazole treatment with regard to complex neuroendocrine regulations of energy homeostasis. Polyinosinic:polycytidylic acid (polyI:C) was administered subcutaneously at a dose of 8 mg/kg in 10 ml on gestational day 15 to female Wistar rats. For this study 20 polyI:C and 20 control adult male offspring were used, randomly divided into 2 groups per 10 animals for chronic aripiprazole treatment and vehicle. Aripiprazole (5 mg/kg, dissolved tablets, ABILIFY®) was administered once daily via oral gavage for a month. Altered lipid profile in polyI:C model was observed and a trend towards different dynamics of weight gain in polyI:C rats was noted in the absence of significant antipsychotic treatment effect. PolyI:C model was not associated with changes in other parameters i.e. adipokines, gastrointestinal hormones and cytokines levels. Aripiprazole did not influence body weight but it induced alterations in neurohumoral regulations. Leptin and GLP‐1 serum levels were significantly reduced, while ghrelin level was elevated. Furthermore aripiprazole decreased serum levels of pro‐inflammatory cytokines. Our data indicate dysregulation of adipokines and gastrointestinal hormones present after chronic treatment with aripiprazole which is considered metabolically neutral in the polyI:C model of schizophrenia. HighlightsPolyI:C model in male rats is associated with increased serum cholesterol.Aripiprazole decreases serum leptin level in the absence of body weight change.Aripiprazole altered GIT hormones suppressing GLP‐1 and elevating ghrelin serum levels.

Macrophage-inhibitory cytokine-1 (mic-1) in differential diagnosis of dyspnea--a pilot study.

BACKGROUND Macrophage inhibitory cytokine-1 (MIC-1) has recently been associated with markers of heart function. AIM This study sought to verify the relationship between markers of heart function (New York Heart Association classification (NYHA)): left ventricle ejection fraction (LVEF), N terminal prohormone of natriuretic peptide B type (NT-proBNP) and MIC-1. Furthermore, the assessment of the usefulness of these markers for differential diagnosis of the myocardial form of dyspnea was explored. METHODS 124 patients (65 women and 59 men) were examined for dyspnea without signs of acute coronary syndrome. All patients underwent echocardiography (calculation of left ventricle ejection fraction-LVEF), and serum NT-proBNP, proguanylin as well as MIC-1 were determined. 21 healthy individuals were defined as the control group. RESULTS AND DISCUSSION Patients were divided into two groups: A--individuals with non-cardiogenic form of dyspnea, n=77 and B--individuals with cardiogenic ethiology of dyspnea, n=47. Significant differences between MIC-1 values in individuals with cardiogenic dyspnea (median 2189.6 ng/L) and non-cardiogenic dyspnea (median 232.1 ng/L) were shown. MIC-1 correlated with age, proguanylin, NT-proBNP and negatively with LVEF (P<0.05). The median values of MIC-1 were closely associated with the NYHA classification (P<0.05). Division of the group under study according to the cause of dyspnea revealed a significant difference in MIC-1 (P<0.01). The cut-off of MIC-1>444.5 ng/L showed 100% sensitivity and 89.3% specificity for diagnosing cardiogenic dyspnea. After adjustment for age, gender and NT-proBNP, MIC-1 levels were significantly associated with the cardiogenic type of dyspnea (P<0.05). We also tested the difference in MIC-1 level among the subgroup with the cardiac form of dyspnea (10 individuals suffered from hypertension and 37 patients had no sign of hypertension). Individuals with and without hypertension had no significant difference in MIC-1 level. CONCLUSION MIC-1 is a new diagnostic marker in the differential diagnosis of dyspnea.