Urocortin 2 (UCN2) is a peptide related to corticotropin-releasing factor, capable of activating CRF-R2. Among its multisystemic effects, it has actions in all 3 muscle subtypes. This study’s aim was to determine its potential role in two of the intrinsic eye muscle kinetics. Strips of iris sphincter (rabbit) and ciliary (bovine) muscles were dissected and mounted in isometric forcetransducer systems filled with aerated-solutions. Contraction was elicited using carbachol (10-6 M for iris sphincter, 10-5 M for ciliary muscle), prior adding to all testing substances. UCN2 induced relaxation in iris sphincter muscle, being the effect maximal at 10-7 M concentrations (-12.2 % variation vs. control). This effect was abolished with incubation of indomethacin, antisauvagine-30, chelerytrine and SQ22536, but preserved with L-nitro-L-arginine. In carbachol pre-stimulated ciliary muscle, UCN2 (10-5 M) enhanced contraction (maximal effect of 18.2 % increase vs. control). UCN2 is a new modulator of iris sphincter relaxation, dependent of CRF-R2 activation, synthesis of prostaglandins (COX pathway) and both adenylate cyclase and PKC signaling pathways, but independent of nitric oxide production. Regarding ciliary muscle, UCN2 enhances carbachol-induced contraction, in higher doses., M. Tavares-Silva, D. Ferreira, S. Cardoso, A. R. Raimundo, J. Barbosa-Breda, A. Leite-Moreira, A. Rocha-Sousa., and Obsahuje bibliografii
We aimed to explore the effects of melatonin and n-3 polyunsaturated fatty acids (PUFA) supplementation on plasma and aortic nitric oxide (NO) levels in isoproterenol (Iso) affected spontaneously hypertensive (SHR) and Wistar rats. Untreated control rats were compared with Iso injected (118 mg/kg, s.c.) rats, and Iso injected plus supplemented with melatonin (10 mg/kg, p.o.) or PUFA (1.68 g/kg, p.o.) for two months. Plasma and aortic basal, L-NAME inhibited, adrenaline and acetylcholine stimulated NO were determined using Griess method. Plasma NO levels were lower in SHR versus Wistar rats. Iso decreased NO in Wistar while not in SHR. PUFA but not melatonin intake of Iso treated SHR increased plasma NO along with a decrease in systolic blood pressure. Basal aortic NO level was higher in SHR than Wistar rats and not altered by Iso. Intake of melatonin increased but PUFA decreased basal NO levels in Wistar+Iso and did not affect in SHR+Iso rats. Acetylcholine and adrenaline induced aortic NO release was significantly increased in Wistar+Iso but not SHR+Iso group. Melatonin intake increased Ach induced aortic NO in Wistar+Iso and SHR+Iso groups, whereas there was no effect of PUFA intake. Findings suggest that PUFA modulates plasma and melatonin aortic NO levels of isoproterenol affected rats in a strain-dependent manner., K. K. Chaudagar, C. Viczenczova, B. Szeiffova Bacova, T. Egan Benova, M. Barancik, N. Tribulova., and Obsahuje bibliografii
Hypericin is a photosensitizing plant pigment from Hypericum perforatum with multiple modes of light-induced biological activities due to production of singlet oxygen and/or excited-state proton transfer with consequent pH drop in the hypericin environment. In the present work, we studied the effects of three inhibitors of crucial mechanisms responsible for intracellular pH (pHi) regulation on hypericin phototoxicity: N-ethylmaleimide (NEM), an inhibitor of H+-ATPase, 5'-(N,N-dimethyl)-amiloride (DMA), an inhibitor of Na+/H+ exchanger, and omeprazole (OME), an inhibitor of H+K+-ATPase. Our experiments show that the effect of hypericin at 1x10-5 and 1x10-6 mol.l-1 was significantly potentiated by NEM (1x10-7-1x10-9 mol.l-1) and DMA (1x10-6 and 1x10-7 mol.l-1) in leukemic CEM cell line. On the other hand, OME had no significant effect on hypericin cytotoxicity. Our results support the hypothesis that the excited-state proton transfer and the consequent acidification of hypericin environment could play a role in the biological activity of hypericin., A. Miroššay, L. Mirossay, M. Šarišský, P. Papp, J. Mojžiš., and Obsahuje bibliografii
Transient receptor potential A1 (TRPA1) is an excitatory ion channel that functions as a cellular sensor, detecting a wide range of proalgesic agents such as environmental irritants an d endogenous products of inflammation and oxidative stress. Topical application of TRPA1 agonists produces an acute nociceptive response through peripheral release of neuropeptides, purines and other transmitters from activated sensory nerve endings. This, in turn, further regulates TRPA1 activity downstream of G-protein and phospholipase C -coupled signaling cascades. Despite the important physiological relevance of such regulation leading to nociceptor sensitization and consequent pain hypersensitivity, th e specific domains through which TRPA1 undergoes post -translational modifications that affect its activation properties are yet to be determined at a molecular level. This review aims at providing an account of our current knowledge on molecular basis of r egulation by neuronal inflammatory signaling pathways that converge on the TRPA1 channel protein and through modification of its specific residues influence the extent to which this channel may contribute to pain., A. Kádková, V. Synytsya, J. Krusek, L. Zímová, V. Vlachová., and Obsahuje bibliografii
Autosomal dominant hypercholesterolemia (ADH), more known as familial hypercholesterolemia (FH), is a lipid metabolism disorder characterized by an elevation in low-density lipoprotein cholesterol (LDL-C) and increased risk for cardiovascular disea se. In this study, we assessed a spectrum of mutations causing ADH in 3914 unrelated Czech patients with clinical diagnosis of hypercholesterolemia. Samples have been collected within the framework of the MedPed project running in the Czech Republic since 1998. So far we have found 432 patients (11.0 %) with the APOB gene mutation p.(Arg3527Gln) and 864 patients (22.1 %) with the LDLR gene mutation. In 864 probands carrying the LDLR gene mutation, 182 unique allelic variants were detected. We have identified 14 patients homozygous for mutations in the LDLR or APOB genes. We performed function analyses of p.(Leu15Pro) and p.(Gly20Arg) sequence variations., L. Tichý, L. Fajkusová, P. Zapletalová, L. Schwarzová, M. Vrablík, T. Freiberger., and Obsahuje bibliografii
This review summarizes recent information on the role of calcium in the process of neuronal injury with special attention to the role of calcium stores in the endoplasmic reticulum (ER). Experimental results present evidence that ER is the site of complex processes such as calcium storage, synthesis and folding of proteins and cell response to stress. ER function is impaired in many acute and chronic diseases of the brain which in turn induce calcium store depletion and conserved stress responses. Understanding the mechanisms leading to ER dysfunction may lead to recognition of neuronal protection strategies., J. Lehotský, P. Kaplán, E. Babušíková, A. Strapková, R. Murín., and Obsahuje bibliografii
Summary The aim of the study was to characterize by molecular profiling two glomerular diseases: IgA nephropathy (IgAN) and focal segmental glomerulosclerosis (FSGS) and to identify potential molecular markers of IgAN and FSGS progression. The expressions of 90 immune-related genes were compared in biopsies of patients with IgAN (n=33), FSGS (n=17) and in controls (n=11) using RT-qPCR. To identify markers of disease progression, gene expression was compared between progressors and non-progressors in 1 year follow-up. The results were verified on validation cohort of patients with IgAN (n=8) and in controls (n=6) using laser-capture microdissection, that enables to analyze gene expression separately for glomeruli and interstitium. In comparison to controls, patients with both IgAN and FSGS, had lower expression of BAX (apoptotic molecule BCL2-associated protein) and HMOX-1 (heme oxygenase 1) and higher expression of SELP (selectin P). Furthermore, in IgAN higher expression of PTPRC (protein-tyrosine phosphatase, receptor-type C) and in FSGS higher expression of BCL2L1 (regulator of apoptosis BCL2-like 1) and IL18 compared to control was observed. Validation of differentially expressed genes between IgAN and controls on another cohort using laser-capture microdissection confirmed higher expression of PTPRC in glomeruli of patients with IgAN. The risk of progression in IgAN was associated with higher expression EDN1 (endothelin 1) (AUC=0.77) and FASLG (Fas ligand) (AUC=0.82) and lower expression of VEGF (vascular endothelial growth factor) (AUC=0.8) and in FSGS with lower expression of CCL19 (chemokine (C-C motif) ligand 19) (AUC=0.86). Higher expression of EDN1 and FASLG along with lower expression of VEGF in IgAN and lower expression of CCL19 in FSGS at the time of biopsy can help to identify patients at risk of future disease progression., I. Tycová, P. Hrubá, D. Maixnerová, E. Girmanová, P. Mrázová, L. Straňavová, R. Zachoval, M. Merta, J. Slatinská, M. Kollár, E. Honsová, V. Tesař, O. Viklický., and Seznam literatury
Purinergic P2X receptors represent a novel structural type of ligand-gated ion channels activated by extracellular ATP. So far, seven P2X receptors subunits have been found in excitable as well as non-excitable tissues. Little is known about their structure, mechanism of channel opening, localization, and role in the central nervous system. The aim of this work is to summarize recent investigations and describe our contribution to elucidating the structure of the ATP binding site and transmembrane domains of the P2X receptor, we also discuss the expression and physiological roles played by the ATP and P2X receptors in the anterior pituitary and hypothalamus., H. Zemková, A. Balík, M. Jindřichová, V. Vávra., and Obsahuje bibliografii a bibliografické odkazy
The study aimed to evaluate if the monitoring of advanced glycation end products (AGEs), advanced oxidation protein products (AOPP), lipoperoxides (LPO) and interleukin-6 (IL-6) in plasma could help to predict development of diabetic complications (DC). Clinical and biochemical parameters including AGEs, AOPP, LPO and IL-6 were investigated in patients with type 2 diabetes mellitus (DM2) with (+DC) and without (-DC) complications. AGEs were significantly higher in both diabetic groups compared to controls. AGEs were also significantly higher in group +DC compared to -DC. AGEs significantly correlated with HbA1c. We observed significantly higher AOPP in both diabetic groups in comparison with controls, but the difference between -DC and +DC was not significant. LPO significantly correlated with BMI. IL-6 were significantly increased in both diabetic groups compared to controls, but the difference between -DC and +DC was not significant. There was no significant correlation between IL-6 and clinical and biochemical parameters. These results do not exclude the association between IL-6 and onset of DC. We suggest that the measurement of not only HbA1c, but also AGEs may be useful to predict the risk of DC development in clinical practice. Furthermore, the measurement of IL-6 should be studied as adjunct to HbA1c monitoring., V. Jakuš, E. Šándorová, J. Kalninová, B. Krahulec., and Obsahuje bibliografii
Although exposure to continuous light is associated with hypertension and modulates the outcome of ischemiareperfusion injury, less attention has been paid to its effects on cardiac morphology. We investigated whether 4-week exposure of experimental rats to continuous 24 h/day light can modify cardiac morphology, with focus on heart weight, fibrosis and collagen I/III ratio in correlation with NO-synthase expression. Two groups of male adult Wistar rats were studied: controls exposed to normal light/dark cycle (12 h/day light, 12 h/day dark) and rats exposed to continuous light. After 4 weeks of treatment the absolute and the relative heart weights were determined and myocardial fibrosis and collagen type I/III ratio were evaluated using picrosirius red staining. Endothelial and inducible NO-synthase expression was detected immunohistochemically. The exposure of rats to continuous light resulted in an increase of body weight with proportionally increased heart weight. Myocardial fibrosis remained unaffected but collagen I/III ratio increased. Neither endothelial nor inducible NO-synthase expression was altered in light-exposed rats. We conclude that the loss of structural homogeneity of the myocardium in favor of collagen type I might increase myocardial stiffness and contribute to functional alterations after continuous light exposure., L'. Paulis, R. Važan, F. Šimko, O. Pecháňová, J. Styk, P. Babál, P. Janega., and Obsahuje bibliografii