Agata Sakowicz

The role of Toll-like receptors in renal diseases

Toll-like receptors (TLRs) have a key role in innate immunity. These receptors recognize both pathogen-associated molecular patterns and molecules that are released from damaged tissue. TLRs mediate signal transduction pathways through the activation of transcription factors that regulate the expression of proinflammatory cytokines and chemokines and are required for the development of adaptive immune responses. TLRs might have an important role in the pathogenesis of renal diseases: their exaggerated activation is associated with ischemic kidney damage, acute kidney injury, end-stage renal failure, acute tubulointerstitial nephritis, acute renal transplant rejection and delayed allograft function. As the results of previous studies concerning the role of TLRs in renal diseases are conflicting, further work is needed to determine the exact role of these receptors and to evaluate strategies to prevent TLR-mediated local inflammation. This Review discusses the evidence supporting a role for TLRs in contrasting bacterial infections and in causing or aggravating renal conditions when TLR activation leads to a harmful inflammatory response.

Genetic variability and the risk of myocardial infarction in Poles under 45 years of age

Introduction Myocardial infarction is caused by the obstruction of an artery in places of atherosclerosis plaque rupture. Endothelial cells during their activation express chemoattractant and adhesion molecules whereas infiltrating inflammatory cells produce enzymes, predisposing a lesion to rupture. Material and methods We investigated the correlation between polymorphisms in the human genes E-selectin (Ser128Arg), ICAM1 (K469E), OLR1 (K167N), MMP1 (1G/2G) and MMP3 (−1612 5A/6A) and the risk of MI in young Poles under 45 years. There was no significant difference in the frequency of single nucleotide polymorphism (SNP) of the studied genes E-selectin (Ser128Arg), ICAM1 (K469E), OLR1 (K167N) and MMP3 (−1612 5A/6A) between patients with MI and controls. Results The analysis of the association of the 1G2G polymorphism with the risk of myocardial infarction indicated an odds ratio (OR) of 5.68 (95% confidence interval [95% CI] 2.60 to 12.36). Other factors associated with myocardial infarction were: smoking (OR 4.12; 95% CI 1.63–10.44), male sex (OR 16.02; 95% CI 5.90–43.46), hypercholesterolaemia (OR 2.74; 95% CI 1.29–5.83) and arterial hypertension (OR 4.56; 95% CI 1.66–14.47). Conclusions We found that only MMP1 1G/2G polymorphism is associated with myocardial infarction in the Polish population of individuals younger than 45 years. Clinical factors seemed to play a greater role in the analysed group.

Circulating endothelial cells in essential thrombocythemia and polycythemia vera: correlation with JAK2-V617F mutational status, angiogenic factors and coagulation activation markers

Angiogenesis plays an important role in the biology of hematological malignancies, including essential thrombocythemia (ET) and polycythemia vera (PV). Some data suggests that it has a role in the pathogenesis of thrombosis, the major clinical problem in ET and PV. The number of different subpopulations of circulating endothelial cells (CECs), plasma levels of vascular endothelial growth factor (VEGF), soluble vascular endothelial growth factor receptor 1 and 2 (sVEGFR-1,2) and placenta growth factor (PlGF) were determined in 30 patients with ET and 16 patients with PV. Correlations between angiogenesis and JAK2-V617F mutational status, risk factors for thrombosis and coagulation activation markers were also assessed. The number of CEC subpopulations, were markedly higher in ET and PV patients, irrespective of JAK2-V617F status, when compared to the control group. The median values of activated CECs were markedly higher in PV patients with WBC >8.7 (×109/l). Significantly higher VEGF plasma levels were found in ET patients and a similar trend was seen in PV patients in relation to healthy volunteers. The plasma levels of sVEGFR-1 were significantly higher, and PlGF levels markedly lower, in the ET and PV group than in controls. Our study also demonstrated markedly increased levels of D-dimer and TAT complexes in the patient groups. In conclusion, we found that angiogenesis, as measured by CEC numbers, is increased in ET and PV patients regardless of JAK2-V617F mutational status. Our results demonstrated that angiogenic cytokines interact with known thrombotic risk factors. We confirmed the coagulation activation in ET and PV patients but found no differences in levels of coagulation activation markers in relation to JAK2-V617F mutational status.

Plasma levels of angiogenic factors and circulating endothelial cells in essential thrombocythemia: correlation with cytoreductive therapy and JAK2–V617F mutational status

Recent studies have shown that angiogenesis plays an important role in the biology of hematological malignancies including essential thrombocythemia (ET). Using cytofluorimetric analysis, the levels of angiogenic factors, as well as the number of circulating endothelial cells (CECs), were determined in 65 patients with ET, including 33 previously untreated and 32 receiving cytoreductive therapy. Correlations between markers of angiogenesis and JAK2–V617F mutational status were also assessed. We found significantly higher levels of vascular endothelial growth factor (VEGF) and markedly decreased levels of placental growth factor in untreated patients with ET with respect to control subjects. VEGF levels were significantly increased in patients with white blood count >8.7 (× 109/L) vs. <8.7 (× 109/L). Furthermore, the levels of VEGF in patients on hydroxyurea (HU) therapy were markedly lower than in untreated patients. It was also demonstrated that the number of all CEC subpopulations (resting, activated, apoptotic, and circulating precursor endothelial cells) was increased in patients with ET in relation to controls, regardless of the JAK2–V617F status, and was not affected by cytoreductive treatment. In conclusion, our study highlights the possible role of angiogenesis in the pathophysiology of ET. It provides evidence that the number of CECs is elevated independently of JAK2–V617F status and is not down-regulated by HU or anagrelide therapy. Our data suggest that VEGF levels are particularly elevated in patients with high leukocytosis. Further investigation should be undertaken to determine the possible role of antiangiogenic therapy in ET.

Soluble ST2 protein in chronic heart failure is independent of traditional factors.

Introduction ST2 protein is the interleukin 33 (IL-33) receptor, whose serum level depends on the biomechanical strain of cardiac myocytes. The aim of this study was to analyse the relationship between soluble ST2 (sST2) level and traditional factors in patients with chronic heart failure. Material and methods Sixty-six patients (mean age 62 years, 75% males) in stable NYHA class I-III with left ventricular ejection fraction < 45% were included in the study. Clinical, biochemical, electrocardiographic, echocardiographic and angiographic data were analysed. Patients were divided into groups depending on sST2 median: > 0.28 ng/ml (n = 31) vs. ≤ 0.28 ng/ml (n = 35). sST2 was measured using a quantitative ELISA kit. In order to define factors associated with sST2 levels uni- and multivariate regression analysis was performed. Results There was no relationship between sST2 levels and age (p = 0.67), body mass index (p = 0.19), hsTnT (p = 0.7) or other analysed parameters (all p > 0.05), except for N-terminal prohormone B-type natriuretic peptide (NT-proBNP). A significant positive correlation between sST2 and NT-proBNP was found (p = 0.013, R = 0.395). Multivariate analysis revealed that the stage of coronary artery disease and NT-proBNP were independent factors associated with sST2 concentration (p = 0.04). Intriguing is the fact that the fewer the sclerotic changes present in arteries, the higher was the sST2 level (β = –0.381, p = 0.04). Conclusions sST2 protein is independent of traditional factors which usually affect levels of NT-proBNP. In chronic heart failure, sST2 protein may be of greater importance in idiopathic dilated cardiomyopathy than in ischaemic aetiology, which seems to be associated with the molecular mechanism (biomechanical strain) related to sST2.

Soluble ST2 protein in the short-term prognosis after hospitalisation in chronic systolic heart failure

BACKGROUND The prognosis in patients with chronic heart failure (CHF) is poor. ST2 protein is a promising prognostic biomarker for CHF. ST2 belongs to the cardioprotective signalling pathway involving interleukin-33 and its concentration in the serum depends on the biomechanical stress of cardiomyocytes (biomechanical strain). AIM To determine the prognostic value of ST2 in short term follow-up after hospitalisation among patients with CHF. METHODS The study included 167 patients (mean age 62 years, 83% men) in stable NYHA class I-III with left ventricular ejection fraction (LVEF) of ≤ 45% (average 29.65%, ranges 13-45%). We analysed 58 variables including: demographics, co-morbidities, resting ECG, echocardiographic and coronary arteriography data, basic laboratory tests including N-terminal prohormone B-type natriuretic peptide (NT-proBNP), serum concentration of soluble form of ST2 (sST2) using quantitative ELISA test ST2 Kit (Medical and Biological Laboratories; Japan) and adverse cardiovascular events during a one year observation. In the study, the primary endpoint (death) and the composite endpoint (hospitalisation for HF worsening, worsening in NYHA functional class, the need to increase the dose of diuretics, and/or death in a one year observation) were determined. RESULTS Patients who died (n = 24; 14.55%) were in more advanced NYHA class, had prolonged QRS duration, higher levels of sST2, NT-proBNP, and lower estimated glomerular filtration rate. From multivariate analysis, the independent variable for the primary endpoint was NT-proBNP (OR = 1.00012; 95% CI 1.00002-1.00022; p = 0.018). 93 (56%) patients reached the composite endpoint. Multivariate analysis revealed that fasting glucose (OR = 1.343; 95% CI 1.041-1.732; p = 0.023) and sST2 (OR = 3.593; 95% CI 1.427-9.05; p = 0.007) independently enhanced the risk of composite endpoint occurrence in a one year observation. CONCLUSIONS In patients with CHF with LVEF ≤ 45%, the prognostic value of sST2 protein in a short-term observation of one year was confirmed. sST2 protein was an independent variable for the composite endpoint, which consisted of worsening NYHA functional class, hospitalisation for worsening of HF, the need to increase the dose of diuretics, and/or death.

Differences in biochemical and genetic biomarkers in patients with heart failure of various etiologies

BACKGROUND/OBJECTIVES To evaluate whether biomarkers reflecting pathophysiological pathways and selected single nucleotide polymorphisms differ between patients (pts) with heart failure (HF). METHODS 110 pts with were involved, including HF pts with preserved ejection fraction (HFpEF, n=51) with hypertensive origin, HF pts with reduced ejection fraction (HFrEF) with ischemic aetiology (ICM) (n=32) and HFrEF with dilated cardiomyopathy (DCM) (n=27). We assessed selected HF biomarkers, echocardiographic examinations and functional polymorphisms selected from six candidate genes: CYP27B1, NOS3, IL-6, TGF beta, TNF alpha, and PPAR gamma. RESULTS Higher concentrations of TNF alpha were observed in pts with hypertensive HFpEF compared to pts with DCM (p=0.008). Pts with HFpEF had higher concentrations of TGF beta 1 compared to DCM and ICM (p=0.0001 and p=0.0003, respectively). For the NOS3 -786 C/T rs2070744 polymorphism in DCM there were significantly more CT heterozygotes than in ICM and HFpEF. In multivariate analysis TGF beta 1 (p=0.001) and syndecan 4 (p=0.001) were the only factors distinguishing HFrEF pts with DCM vs HFpEF and also TGF beta 1 (p=0.001) and syndecan 4 (p=0.023) were the only factors distinguishing HFrEF pts with ICM vs HFpEF pts. CONCLUSIONS Inflammation mediated through TNF alpha and TGF beta 1 may represent an important component of an inflammatory response that partially drives the pathophysiology of HFpEF. NOS3 -786 C/T rs2070744 polymorphism in DCM may serve as a marker for more rapid progression of heart failure. The only biomarkers independently distinguishing HFpEF and HFrEF are syndecan 4 and TGF beta 1.

Two polymorphisms of the FVII gene and their impact on the risk of myocardial infarction in poles under 45 years of age

High levels of coagulation factor VII (FVII) in plasma have been associated with the increased risk of myocardial infarction (MI) in some studies. Both environmental and genetic factors are responsible for different levels of FVII in plasma. In the FVII gene there are two common polymorphisms (−323A1/A2 and IVS7) which are related to the level of FVII. The purpose of this study was to evaluate the influence of these polymorphisms on the risk of acute myocardial infarction in Poles under 45 years of age. We performed a case-control study of 266 patients with the history of MI. All patients had the first incidence of MI before 45 years of age. The control group consisted of 137 healthy individuals older than 45 years. Carriers of the A2 allele (−323A1/A2 polymorphism) have a lower risk of MI than non-carriers (OR = 0.40, 95% CI = 0.20−0.80). The IVS7 polymorphism was shown not to be related to MI in this study. Our findings suggest that the −323A1/A2 polymorphism of the FVII gene is related to the risk of MI in Polish individuals. We pointed that plasma cholesterol (OR = 1.11, 95% CI = 1.03−1.18), arterial hypertension (OR = 3.84, 95% CI = 1.99−7.43) and family history (OR = 2.72, 95% CI = 1.57−4.73) are significant predictors of acute myocardial infarction.

Sphingolipids as a new factor in the pathomechanism of preeclampsia – Mass spectrometry analysis

Objective(s) and design The aim of the study was to analyse a panel of 11 sphingolipids in plasma and three blood fractions (platelet-poor plasma, platelets and red blood cells) of women with mild preeclampsia. Materials and methods We recruited 21 women between 25–40 weeks gestation with diagnosed mild preeclampsia to the study group and 36 healthy women with uncomplicated pregnancies, who corresponded with the study group according to gestational age, to the control group. To assess the concentration of 11 sphingolipids in the blood plasma and blood fractions, we used ultra-high performance liquid chromatography coupled with triple quadrupole mass spectrometry (UHPLC/MS/MS). Results We showed a significant increase in the concentration of eight sphingolipids in the plasma of women with preeclampsia in comparison to the control group: Sph (p = 0.0032), S1P (p = 0.0289), C20-Cer (p < 0.0001), C18-Cer (p < 0.0001), C16-Cer (p = 0.012), C18:1-Cer (p = 0.003), C22-Cer (p = 0.0071), and C24:1-Cer (p = 0.0085). Conclusion We showed that selected sphingolipids, especially C20-Cer and C18-Cer, are totally new factors in the pathomechanism of PE and that these bioactive lipids may play an important role in apoptosis and autophagy.

Angiogenic factor screening in women with mild preeclampsia – New and significant proteins in plasma

HighlightsIncrease in the concentration of 8 proteins in the plasma of women with preeclampsia.IFN‐&ggr;, IL‐6, LIF, Hb‐EGF, HGF, IP‐10, leptin, PDGF‐BB.Significant decrease in the concentration of 3 proteins in the plasma of women with preeclampsia.VEGF, PlGF and follistatin. Introduction The aim of this study was to analyse a panel of 60 angiogenic factors (pro‐angiogenic and antiangiogenic) in the plasma of women with mild preeclampsia. Materials and Methods We recruited 21 women between 25 and 40 weeks gestation with diagnosed mild preeclampsia into the study group and 27 healthy women with uncomplicated pregnancies of corresponding gestational age to that of the study to the control group. We used a quantitative protein macroarray method that allowed for analysis of 60 angiogenic proteins per sample simultaneously. Results We showed a statistically significant increase in the concentration of 8 proteins, interferon gamma (IFN‐&ggr;), interleukin 6 (IL‐6), leukaemia inhibitory factor (LIF), heparin‐binding EGF‐like growth factor (HB‐EGF), hepatocyte growth factor (HGF), C‐X‐C motif chemokine 10 (IP‐10), leptin and platelet‐derived growth factor BB (PDGF‐BB), as well as a significant decrease in the concentration of 3 proteins, vascular endothelial growth factor (VEGF), placental growth factor (PlGF) and follistatin, in the plasma of women with preeclampsia. Conclusion Based on our findings, it seems that protein factors may play an important role in the pathogenesis of preeclampsia, and there are many proteins that have not been studied in PE to date. There are no previous studies assessing the LIF, follistatin, HGF, HB‐EGF and PDGF‐BB concentrations in the plasma of women with PE; therefore, our obtained results indicate that these proteins are new factors that can play an important role in the pathomechanisms of PE.