Neurodegenerative disorders, such as Alzheimer’s disease (AD) and Parkinson’s disease (PD), are increasing in prevalence. Currently, there are no effective and specific treatments for these disorders. Recently, positive effects of the orexigenic hormone ghrelin on memory and learning were demonstrated in mouse models of AD and PD. In this study, we tested the potential neuroprotective properties of a stable and long-lasting ghrelin analog, Dpr3ghrelin (Dpr3ghr), in SH-SY5Y neuroblastoma cells stressed with 1.2 mM methylglyoxal (MG), a toxic endogenous by-product of glycolysis, and we examined the impact of Dpr3ghr on apoptosis. Pre-treatment with both 10-5 and 10-7 M Dpr3ghr resulted in increased viability in SH-SY5Y cells (determined by MTT staining), as well as reduced cytotoxicity of MG in these cells (determined by LDH assay). Dpr3ghr increased viability by altering pro-apoptotic and viability markers: Bax was decreased, Bcl-2 was increased, and the Bax/Bcl-2 ratio was attenuated. The ghrelin receptor GHS-R1 and Dpr3ghr-induced activation of PBK/Akt were immuno-detected in SH-SY5Y cells to demonstrate the presence of GHS-R1 and GHS-R1 activation, respectively. We demonstrated that Dpr3ghr protected SH-SY5Y cells against MG-induced neurotoxicity and apoptosis. Our data suggest that stable ghrelin analogs may be candidates for the effective treatment of neurodegenerative disorders., A. Popelová, A. Kákonová, L. Hrubá, J. Kuneš, L. Maletínská, B. Železná., and Seznam literatury
Summary Mitochondria are exposed to reactive nitrogen species under physiological conditions and even more under several pathologic states. In order to reveal the mechanism of these processes we studied the effects of peroxynitrite on isolated beef heart mitochondria in vitro. Peroxynitrite has the potential to nitrate protein tyrosine moieties, break the peptide bond, and eventually release the membrane proteins into the solution. All these effects were found in our experiments. Mitochondrial proteins were resolved by 2D electrophoresis and the protein nitration was detected by immunochemical methods and by nano LC-MS/MS. Mass spectrometry confirmed nitration of ATP synthase subunit beta, pyruvate dehydrogenase E1 component subunit beta, citrate synthase and acetyl-CoA acetyltransferase. Immunoblot detection using chemiluminiscence showed possible nitration of other proteins such as cytochrome b-c1 complex subunit 1, NADH dehydrogenase [ubiquinone] ironsulfur protein 2, elongation factor Tu, NADH dehydrogenase [ubiquinone] flavoprotein 2, heat shock protein beta-1 and NADH dehydrogenase [ubiquinone] iron-sulfur protein 8. ATP synthase beta subunit was nitrated both in membrane and in fraction prepared by osmotic lysis. The high sensitivity of proteins to nitration by peroxynitrite is of potential biological importance, as these enzymes are involved in various pathways associated with energy production in the heart., M. Kohutiar, A. Eckhardt, I. Mikšík, P. Šantorová, J. Wilhelm., and Seznam literatury
Red palm oil (RPO) is a rich natural source of antioxidant vitamins, namely carotenes, tocopherols and tocotrienols. However, it contains approximately 50 % saturated fatty acids the regular consumption of which could negatively modify lipid profile. The aim of our study was to test whether 7 weeks of RPO supplementation (1 g/kg body weight/day) would affect blood glucose and lipid metabolism in adult male Wistar rats with altered thyroid status. We induced hypothyroidism and hyperthyroidism in rats by oral administration of either methimazole or mixture of thyroid hormones. Different thyroid status (EU - euthyroid, HY - hypothyroid and HT - hyperthyroid) was characterized by different serum thyroid hormones levels (total and free thyroxine and triiodothyronine), changes in the activity of a marker enzyme of thyroid status - liver mitochondrial glycerol-3-phosphate dehydrogenase, and altered absolute and relative heart weights. Fasting blood glucose levels were higher in HT rats in comparison with EU and HY rats, but the changes caused by RPO supplementation were not significant. The achievement of the HY status significantly increased serum levels of total cholesterol, as well as with high-density lipoproteincholesterol and low-density lipoprotein-cholesterol: 2.43±0.15, 1.48±0.09, 0.89±0.08 mmol/l, compared to EU: 1.14±0.06, 0.77±0.06, 0.34±0.05 mmol/l and HT: 1.01±0.06, 0.69±0.04, 0.20±0.03 mmol/l, respectively. RPO supplementation did not increase significantly levels of blood lipids but tended to increase glutathione levels in the liver. In conclusion, RPO supplementation did not induce the presumed deterioration of glucose and lipid metabolism in rats with three well-characterized alterations in thyroid status., H. Rauchová, M. Vokurková, S. Pavelka, I. Vaněčková, N. Tribulová, T. Soukup., and Seznam literatury
Chronic kidney disease (CKD) is a life-threatening disease arising as a frequent complication of diabetes, obesity and hypertension. Since it is typically undetected for long periods, it often progresses to end-stage renal disease. CKD is characterized by the development of progressive glomerulosclerosis, interstitial fibrosis and tubular atrophy along with a decreased glomerular filtration rate. This is associated with podocyte injury and a progressive rise in proteinuria. As endothelin-1 (ET-1) through the activation of endothelin receptor type A (ETA) promotes renal cell injury, inflammation, and fibrosis which finally lead to proteinuria, it is not surprising that ETA receptors antagonists have been proven to have beneficial renoprotective effects in both experimental and clinical studies in diabetic and non-diabetic CKD. Unfortunately, fluid retention encountered in large clinical trials in diabetic CKD led to the termination of these studies. Therefore, several advances, including the synthesis of new antagonists with enhanced pharmacological activity, the use of lower doses of ET antagonists, the addition of diuretics, plus simply searching for distinct pathological states to be treated, are promising targets for future experimental studies. In support of these approaches, our group demonstrated in adult subtotally nephrectomized Ren-2 transgenic rats that the addition of a diuretic on top of renin-angiotensin and ETA blockade led to a further decrease of proteinuria. This effect was independent of blood pressure which was normalized in all treated groups. Recent data in non-diabetic CKD, therefore, indicate a new potential for ETA antagonists, at least under certain pathological conditions., I. Vaněčková, S. Hojná, M. Kadlecová, Z. Vernerová, L. Kopkan, L. Červenka, J. Zicha., and Seznam literatury
Spexin (SPX) and kisspeptin (KISS) are novel peptides relevant in the context of regulation of metabolism, food intake, puberty and reproduction. Here, we studied changes of serum SPX and KISS levels in female non-obese volunteers (BMI<25 kg/m2) and obese patients (BMI>35 kg/m2). Correlations between SPX or KISS with BMI, McAuley index, QUICKI, HOMA IR, serum levels of insulin, glucagon, leptin, adiponectin, orexin-A, obestatin, ghrelin and GLP-1 were assessed. Obese patients had lower SPX and KISS levels as compared to non-obese volunteers (SPX: 4.48±0.19 ng/ml vs. 6.63±0.29 ng/ml; p<0.001, KISS: 1.357±0.15 nmol/l vs. 2.165±0.174 nmol/l; p<0.01). SPX negatively correlated with BMI, HOMA-IR, insulin, glucagon, active ghrelin and leptin. Positive correlations were found between SPX and QUICKI index, McAuley index, serum levels of obestatin, GLP-1 and adiponectin and orexin-A Serum KISS negatively correlated with BMI, HOMA-IR, serum levels of insulin, glucagon, active ghrelin and leptin. KISS positively correlated with QUICKI index, McAuley index and adiponectin. In summary, SPX and KISS show negative correlations with obesity, insulin resistance indices, and hormones known to affect insulin sensitivity in females. Both, SPX and KISS could be therefore relevant in the pathophysiology of obesity and insulin resistance., P. A. Kołodziejski, E. Pruszyńska-Oszmałek, E. Korek, M. Sassek, D. Szczepankiewicz, P. Kaczmarek, L. Nogowski, P. Maćkowiak, K. W. Nowak, H. Krauss, M. Z. Strowski., and Seznam literatury
Sleep apnoea (SA) is common in patients with hypertension. Nowadays, limited data on the prevalence of SA in nocturnal hypertension (NH) exist. Therefore, we studied the occurrence of SA in Czech patients and its association with 24-h ambulatory blood pressure monitoring (ABPM), breathing disturbances in sleep, anthropometric data, Mallampati score and Epworth sleepiness scale (ESS) using the Apnea Link device. Undiagnosed SA was found in 72.9 % patients (29.3 % mild, 26.6 % moderate, 17.0 % severe) of 188 patients with NH measured by ABPM. The median of the apnoea-hypopnoea index (AHI) was 12.0 (25th-75th percentile 5.0-23.8). Moderate/severe SA (AHI≥15) was associated with BMI, waist circumference, mean night saturation (SpO2), t90, oxygen desaturation index (ODI), ESS (daytime BP only) (p≤0.032), but not ABPM parameters and Mallampati score (p>0.09). A likelihood of moderate/severe SA was enhanced by ODI>14.5 events/h (odds ratio=57.49, 95 % CI=22.79-145.01), t90>6.5 % (8.07, 4.09-15.92), mean night SpO2<93.5 % (3.55, 1.92-6.59), BMI>29.05 kg/m2 (6.22, 3.10-12.49), circum waist>105.5 cm (3.73, 1.57-8.83), but not by any ABPM parameter. In conclusion, a high incidence of SA (72.9 %) was observed in Czech patients with NH. SA severity was associated with body characteristics and oxygenation parameters, but not with ABMP parameters and Mallampati score., M. Hobzová, K. Šonka, M. Pretl, J. Václavík, E. Kriegová, M. Radvanský, J. Zapletalová, M. Placková, V. Kolek., and Seznam literatury
Electric stimulation (ES) could induce contraction of intestinal smooth muscle. The aim of this study was to analyze the effects of ES on esophageal motility and the underlying mechanism in vivo. Twenty-eight rabbits were equipped with a pair of subserosa electrodes (connected to an electrical stimulator) in the lower segment of the esophagus. The ES signal consisted of bipolar rectangular pulse trains, lasting for 3 s, with different amplitudes (1 mA, 3 mA, 5 mA and 10 mA), and frequencies (10 Hz, 20 Hz and 50 Hz). The amplitude of the contraction was recognized by high-resolution manometry. The effect of ES was tested under anesthesia and following administration of atropine, phentolamine or L-NAME. ES induced esophageal contraction at the stimulated site. A statistically significant increase in esophageal pressure was observed when the stimulation amplitude was above 3 mA. The increase in esophageal pressure was associated with the amplitude of stimulus as well as the frequency. During stimulation, atropine, phentolamine and L-NAME had no effect on the increase of esophageal pressure induced by ES. These findings implied that ES induced esophageal contraction were not mediated via the NANC, adrenergic or cholinergic pathway. The amplitude of esophageal contraction was current and frequency dependent., L. Zhang, W. Zhao, C. Zhao, H. Jin, B. Wang, B. Wang., and Seznam literatury
The first trimester of pregnancy is characterized by continuous proliferation, invasion and differentiation of cytotrophoblasts. These processes are precisely controlled both, in space and time by molecules such as endothelin-1 (ET-1). ET-1 is expressed in human first trimester trophoblast and is known to stimulate cytotrophoblast proliferation through endothelin A and B receptor subtypes (ETA and ETB), and cytotrophoblast invasion through ETB. However, temporal changes of the ET system during the first trimester of pregnancy have not been previously studied. This study tested the hypothesis that ET-1 release, ETA and ETB expression are increased towards the end of the first trimester of pregnancy (weeks 10-12 vs. weeks 6-9), resulting in increased cytotrophoblast proliferation and invasion. Tissue samples were obtained from 17 surgical pregnancy interruptions (week 6-9: n=9; week 10-12: n=8). After cytotrophoblast isolation, the invasive and proliferative phenotypes were immune-separated by an α6-integrin antibody. Both proliferative and invasive cytotrophoblasts were cultured separately on plastic or Matrigel for 24 h. ET-1 release into the culture medium of both cytotrophoblast subtypes was measured by radioimmunoassay. ETA and ETB mRNA expression was measured by RT-PCR, and the ET-1 effect on cytotrophoblast proliferation and invasion was determined using proliferation and invasion assays, respectively. ET-1 release increased from early to late first trimester of pregnancy in both proliferative (1.8-4.5 fold) and invasive cytotrophoblasts (9.3-28 fold), especially when cultured on Matrigel. This was paralleled by less ETB mRNA on invasive cytotrophoblasts independent of the time period in first trimester, whereas ETA expression was similar on proliferative an invasive cytotrophoblasts. Proliferation and invasion of cytotrophoblasts under control conditions decreased from early to late first trimester. The ET-1/ET-receptor system changes between weeks 6-9 and 10-12 in pregnancy. Our data suggest an autocrine and endocrine ET-1 effect, which is stronger in late than in early first trimester of pregnancy paralleled by different stimulatory effects on trophoblast invasion and proliferation. In general, this suggests time as an additional effector of the critical processes governing placental development in the first trimester of human pregnancy., A. Majali-Martinez, S. Barth, U. Lang, G. Desoye, M. Cervar-Zivkovic., and Seznam literatury
The role of the glycocalyx of arterial resistance vessels in regulating blood flow in vivo is not fully understood. Therefore, the effect of glycocalyx damage using two separate compounds, hyaluronidase and N-Formylmethionyl-leucyl-phenylalanine (fMLP), was evaluated in the iliac artery vascular bed of the anaesthetised pig. Blood flow and pressure were measured in the iliac, an adjustable snare was applied to the iliac above the pressure and flow measurement site to induce step decreases (3 occlusions at 3-4 min intervals were performed for each infusion) in blood flow, and hence iliac pressure, and vascular conductance (flow/pressure) was calculated. Saline, hyaluronidase (14 and 28 μg/ml/min), and fMLP (1 μM/min) were infused separately, downstream of the adjustable snare and their effect on arterial conductance assessed. Hyaluronidase at the higher infusion rate and fMLP both caused a reduction in arterial conductance, and hence an increase in blood flow resistance. In conclusion, the results show that glycocalyx damage causes an increase in resistance to blood flow in the iliac artery vascular bed., T. Ruane-O’Hora, F. Markos., and Seznam literatury
Primary aldosteronism (PA) is associated with objectively measured lower physical fitness and blunted response of the renin-angiotensin-aldosterone system to exercise. The purpose of this pilot study was to objectively measure exercise response of the renin-angiotensin-aldosterone system and cardiopulmonary fitness changes after laparoscopic adrenalectomy (ADE) in patients with unilateral PA. We examined a total of 14 patients with confirmed PA before and after ADE, by means of spiroergometry and hormonal evaluation. As expected, after adrenalectomy basal aldosterone (Aldo) levels before exercise decreased significantly, with a concomitant increase in plasma renin (PR). The increase in Aldo (285.9±171.3 to 434.1± 278.2 ng/l; p=0.02) and blunted increase in PR (7.1±0.4 to 8.9±10.4 pg/ml; NS) post-exercise before ADE became significant after ADE Aldo post-ADE (46.8±18.8 to 106.5± 68.1 ng/l; p<0.0001) and PR post-ADE (20.1±14.5 to 33.9± 30.7 pg/ml; p=0.014). After adrenalectomy, the patients had a non-significant increase in peak workload and VO2peak. We found normalization of the renin-angiotensin-aldosterone system response to exercise with little changes in cardiopulmonary fitness six months after ADE., V. Tuka, M. Matoulek, J. Rosa, O. Petrák, O. Mikeš, Z. Krátká, B. Štrauch, R. Holaj, T. Zelinka, J. Widimský., and Seznam literatury