Violetta Dziedziejko

Plasma concentrations of TNF-α and its soluble receptors sTNFR1 and sTNFR2 in patients with coronary artery disease

Tumour necrosis factor alpha (TNF-alpha) is implicated in post-ischemic myocardial dysfunction. Two distinct TNF-alpha receptors are shed from cell membranes and circulate in plasma as soluble sTNFR1 and sTNFR2 proteins. The aim of the study was to establish factors associated with plasma concentrations of TNF-alpha and its receptors in patients with coronary artery disease (CAD). Since adenosine inhibits the expression of TNF-alpha, two functional polymorphisms in genes encoding enzymes participating in adenosine metabolism, i.e. AMP deaminase-1 (AMPD1, C34T) and adenosine deaminase (ADA, G22A), were analyzed. Plasma concentrations of TNF-alpha, sTNFR1, and sTNFR2 were measured using ELISA in 167 patients with CAD. Common factors significantly associated with higher TNF-alpha, sTNFR1, and sTNFR2 were lower glomerular filtration rate (GFR), older age, higher BNP, lower blood haemoglobin, and the presence of asthma or chronic obstructive pulmonary disease (COPD). Higher TNF-alpha and sTNFR1 concentrations were also associated with the presence of heart failure (HF), lower ejection and shortening fraction, the presence of diabetes or metabolic syndrome, lower serum HDL cholesterol, and higher uric acid. In multivariate analysis the common independent predictors of higher TNF-alpha, sTNFR1, and sTNFR2 were lower GFR, lower HDL cholesterol, higher BNP, and the presence of asthma or COPD. There were no associations between AMPD1 C34T or ADA G22A genotypes and TNF-alpha or its receptors. In conclusion, the concentrations of TNF-alpha, sTNFR1, and sTNFR2 reflect the impairment of cardiac and renal function in patients with CAD. Metabolic syndrome and diabetes are associated with higher plasma concentrations of TNF-alpha and its receptors.

Elevated Plasma Levels of C3a Complement Compound in the Exudative Form of Age-Related Macular Degeneration

Aim: Recent findings suggest that chronic inflammatory processes play a role in the progression of age-related macular degeneration (AMD). Here we asked whether the development of different forms of AMD is connected with the elevation of plasma C3a-desArg concentration. Methods: We recruited 30 subjects with a clinical diagnosis of exudative AMD with newly diagnosed choroidal neovascularization (CNV), 30 subjects with dry AMD and 30 age- and sex-matched volunteers without AMD. The concentration of C3a-desArg complement compound was measured in the subjects’ peripheral blood. We evaluated the association between the level of C3a-desArg and age, sex, smoking, atherosclerosis, and hypertension. Results: We found that the levels of C3a-desArg were significantly elevated in patients with exudative AMD compared to the control group. The concentrations of C3a-desArg in patients with dry AMD were similar to those of controls. Additionally, patients and controls with documented atherosclerosis (AS) displayed significantly higher levels of C3a-desArg compared to subjects without AS. Conclusions: Our results suggest an association between systemic complement activation and the development of CNV. Moreover, we found an association of complement activation with atherosclerosis and confirmed the hypothesis that AMD can be a local manifestation of systemic disease.

Increased circulating endothelial progenitor cells in patients with haemorrhagic and ischaemic stroke: The role of Endothelin-1

Ischaemic stroke induces endothelial progenitor cell (EPC) mobilisation from bone marrow into peripheral blood. Circulating EPCs play an important role in post-injury regeneration of vasculature, whereas endothelial cells (ECs) have been shown to reflect endothelial damage and may be responsible for increased Endothelin-1 (ET-1) expression. We investigated herein the association between numbers of circulating ECs and EPCs, the levels of soluble factors regulating their migration and function, and the clinical outcome in patients with haemorrhagic (HS) or ischaemic stroke (IS). Sixteen patients with HS and eighteen with IS were assessed during the first 24h, day 3, and day 7 after stroke and compared them with twenty-three control subjects. We found elevated EPC and EC concentrations using flow cytometry and increase in VEGF, SDF-1, HGF, and ET-1 plasma levels by ELISA in the HS patients, while ET-1 mRNA expression in peripheral blood cells was elevated in the IS patients. Significant correlations were observed between EPCs or ECs and Big ET-1 protein or mRNA levels in HS but not in the IS patients. We suggest that ET-1 may play a role in pathophysiology of stroke and subsequent EPC mobilisation; however, further studies aimed at the precise elucidation of this issue are required.

Conjugated linoleic acid increases intracellular ROS synthesis and oxygenation of arachidonic acid in macrophages

OBJECTIVE Conjugated linoleic acids (CLAs) have potential antiatherosclerotic properties: they may inhibit atherosclerotic processes by reducing the intensity of inflammatory processes. However, in vivo studies have shown that the application of trans-10, cis-12 CLA in obese men increased their oxidative stress. The objective of this study was to determine whether CLA can lead to an increase in oxidative stress and to isoprostane synthesis in macrophages. METHODS Monocytes from peripheral blood and human monocytic leukemia cells were used in this study. Monocytes were differentiated to macrophages, and were incubated with 30 microM cis-9, trans-11 CLA and trans-10, cis-12 CLA or linoleic acid for 2 days. In some experiments the inhibitors of peroxisome proliferator-activated receptor-alpha (PPAR-alpha) or respiratory chain were added. After incubation, synthesis of reactive oxygen species (ROS), total cellular concentration of adenosine triphosphate, concentration of 8-epi-prostaglandin F2 alpha, activity of cytoplasolic phospholipase A2 (cPLA2), activity of mitochondria, and expression of mRNA of PPAR-alpha were measured. RESULTS In cells cultured with CLAs intercellular ROS synthesis increased. In this condition the mitochondrial energy potential was high, and the inhibitors of the respiratory chain and PPAR-alpha reduced ROS concentration. At the same time, the cPLA2 activity was abolished. In contrast, 8-iPF2 alpha III synthesis increased in CLA cells. CONCLUSION Cultivation of cells with CLA leads to an increased ROS synthesis, partly by PPAR-alpha mechanism. An increase in ROS concentration and inhibition of cPLA2 activity can stimulate oxygenation of arachidonic acid and contribute to an increase in 8-epi-PF2 alpha III level and in the apoptosis process in macrophages.

P2X and P2Y receptors—role in the pathophysiology of the nervous system.

Purinergic signalling plays a crucial role in proper functioning of the nervous system. Mechanisms depending on extracellular nucleotides and their P2 receptors also underlie a number of nervous system dysfunctions. This review aims to present the role of purinergic signalling, with particular focus devoted to role of P2 family receptors, in epilepsy, depression, neuropathic pain, nervous system neoplasms, such as glioma and neuroblastoma, neurodegenerative diseases like Parkinson’s disease, Alzheimer’s disease and multiple sclerosis. The above-mentioned conditions are associated with changes in expression of extracellular ectonucleotidases, P2X and P2Y receptors in neurons and glial cells, as well as releasing considerable amounts of nucleotides from activated or damaged nervous tissue cells into the extracellular space, which contributes to disturbance in purinergic signalling. The numerous studies indicate a potential possibility of using synthetic agonists/antagonists of P2 receptors in treatment of selected nervous system diseases. This is of particular significance, since numerous available agents reveal a low effectiveness and often produce side effects.

Expression of genes involved in xenobiotic metabolism and transport in end-stage liver disease: up-regulation of ABCC4 and CYP1B1

BACKGROUND Expression of drug-metabolizing enzymes and drug transporters in liver is mainly regulated by a system of nuclear receptors. The aim of the current study was to investigate the expression of nuclear receptors, as well as these enzymes and transporters, in liver samples from patients suffering from end-stage liver disease of various etiologies (HCV infection, alcohol liver disease, and primary sclerosis cholangitis). METHODS Gene expression was measured using quantitative real-time PCR with surgical specimens from livers of patients with end-stage liver disease, and non-tumoral liver tissue that served as control. RESULTS Our study confirmed that the expression of most phase I enzymes is suppressed in end-stage liver disease, and is correlated with a decrease in NR1I2 and NR1I3, the main regulators of xenobiotic metabolism. While mRNA levels of phase II enzymes were generally unchanged, some ABC transporters were up-regulated. The most spectacular increases in expression were observed with ABCC4 (MRP4) - at the mRNA level, and CYP1B1 - at both the mRNA and protein levels. We also demonstrated that IL-6 can induce CYP1B1 expression independently of CYP1A1, in a human hepatocellular liver carcinoma cell line. CONCLUSIONS As CYP1B1 is an enzyme which converts various substrates into carcinogenous metabolites, its overexpression in liver may be one of the factors increasing the risk of hepatic cancers in patients with liver disease. CYP1A1 and CYP1B1 are often referred to as model AHR target genes, but CYP1A1 was down-regulated in diseased liver samples. This points to the existence of differences in regulation of these two genes.

The effect of exon (19C>A) dihydroorotate dehydrogenase gene polymorphism on rheumatoid arthritis treatment with leflunomide

OBJECTIVE Leflunomide is an isoxazole derivative structurally and functionally unrelated to other known immunomodulatory drugs. The main molecular target of leflunomide is dihydroorotate dehydrogenase (DHODH), a key enzyme of de novo pyrimidine synthesis. The human DHODH gene sequence is highly conserved and contains only one common missense polymorphism in the coding regions. This SNP (refSNP ID: rs3213422) is localized in the first exon of the DHODH gene (19C>A) and leads to Gln7Lys amino acid substitution in the cationic N-terminal region of the DHODH polypeptide, and it has not yet been investigated in relation to enzyme activity or DHODH inhibitor efficacy. The aim of the study was to examine the effect of this polymorphism on leflunomide treatment outcome in rheumatoid arthritis (RA) patients. MATERIALS & METHODS The study was carried out on 147 patients (123 women, 24 men, mean age: 52.8 +/- 11.03 years) diagnosed with RA and treated with leflunomide 20 mg daily. Clinical improvement was evaluated according to the American College of Rheumatology 20% and 50% response criteria. RESULTS The frequency of remission was increased in C allele carriers compared with patients with the A allele. CONCLUSION The results of this study suggest that DHODH polymorphism may be associated with leflunomide treatment outcome in RA patients.

Different populations of circulating endothelial cells in patients with age-related macular degeneration: a novel insight into pathogenesis.

PURPOSE Circulating endothelial cells (CECs) and endothelial progenitor cells (EPCs) may serve as novel markers of endothelial dysfunction. The presence and clinical implications of CECs and the expression of endothelin (ET)-1, one of the most potent vasoconstrictors, have not been evaluated in patients with the neovascular form of age-related macular degeneration (AMD). This study was conducted to determine the different populations of endothelial cells (ECs) in the peripheral blood of AMD patients and to correlate these findings with the expression of ET-1 and the cytokines and growth factors responsible for EC migration and function. METHODS Peripheral blood samples were collected from 29 patients with diagnosed neovascular AMD and from 38 healthy control subjects. CD133(-)CD144(+) CECs and CD34(+)CD133(+)CD144(+) EPCs were counted and analyzed by flow cytometry. The intracellular expression of ET-1 in peripheral blood nuclear cells (PBNCs) was studied by using qRT-PCR, Western blot, and immunocytofluorescence assays, and ET-1, IGF-1, VEGF, SDF-1, and HGF plasma concentrations were measured in enzyme-linked immunosorbent assays. RESULTS Increased CECs and EPCs were found in the AMD patients compared with the counts in healthy individuals. The expression of intracellular ET-1 was significantly elevated in PBNCs from the AMD patients compared with the control subjects. In addition a significantly higher plasma concentration of IGF-1 was observed, but a lower SDF-1 level in the group of AMD patients. CONCLUSIONS These findings suggest that circulating endothelial cells, together with high ET-1 content, may contribute to the development of AMD. Further prospective investigations on the mechanism involved may be relevant to the potential treatment of this disease.

The association of IL-1β, IL-2, and IL-6 gene polymorphisms with bone mineral density and osteoporosis in postmenopausal women

OBJECTIVE Osteoporosis is a common disorder with a strong genetic component. The genetics of osteoporosis impacts on the prediction, diagnosis, prognosis, and treatment of the disease. STUDY DESIGN The aim of the present study was to examine associations between cytokine gene polymorphisms (IL-1beta, IL-2, IL-6) and bone mineral density (BMD) values in postmenopausal women. The study included 226 postmenopausal women with a diagnosed BMD T-score lower than -2.5 SD (mean: -3.02+/-.053) and 224 postmenopausal women with a BMD T-score greater than -2.5 SD (mean: -1.33+/-0.51). RESULTS Among the women with T-scores below -2.5 SD, the BMD values were significantly lower in the carriers of the IL-6 GG genotype compared with those with the CC and GC genotypes (0.70+/-0.38 vs. 0.73+/-0.25 and 0.74+/-0.23 for the lumbar spine, 0.54+/-0.18 vs. 0.56+/-0.15 and 0.58+/-0.22 for the femoral neck). There were no statistically significant associations between the IL-1beta and IL-2 genotypes and BMD values in the group of women with T-scores below -2.5 SD. CONCLUSION The results of the present study suggest an association of the IL-6 -174 G/C polymorphism with osteoporosis in postmenopausal women.

The influence of 3,3′,5-triiodo-l-thyronine on human haematopoiesis

Abstract.  Objectives: Thyroid hormones mediate many physiological and developmental functions in humans. The role of the 3,3′,5‐triiodo‐l‐thyronine (T3) in normal human haematopoiesis at the cellular and molecular levels has not been determined. In this study, it was revealed that the human haematopoietic system might be directly depended on T3 influence. Materials and methods: We detected the TRα1 and TRβ1 gene expression at the mRNA level in human cord blood, peripheral blood and bone marrow CD34+‐enriched progenitor cells, using the RT‐PCR method. Furthermore, we performed Western blotting to prove TRα1 and TRβ1 expression occurs at the protein level in human cord blood, peripheral blood and bone marrow CD34+ cells. In addition, the examined populations of cells were exposed in serum‐free conditions to increasing doses of T3 and were subsequently investigated for clonogenic growth of granulocyte‐macrophage colony‐forming unit and erythrocyte burst‐forming unit in methylcellulose cultures, and for the level of apoptosis, by employing annexin V staining and the terminal deoxynucleotidyltransferase‐mediated dUTP nick‐end labelling method. We investigated expression levels of apoptosis‐related Bax and antiapoptotic Bcl‐2 and Bcl‐xL genes in the examined cells. Results: We found that exposure to higher and lower than normal concentration of thyroid hormone significantly influenced clonogenecity and induced apoptosis in human haematopoietic progenitor cells. Conclusions: This study expands the understanding of the role of thyroid disorders in normal human haematopoiesis and indicates a direct influence of T3 on this process.