MicroRNAs (miRNAs) are important regulators of heart function and then an intriguing therapeutic target for plenty of diseases. The problem raised is that many data in this area are contradictory, thus limiting the use of miRNA-based therapy. The goal of this review is to describe the hub-mechanisms regulating the biogenesis and function of miRNAs, which could help in clarifying some contradictions in the miRNA world. With this scope, we analyse an array of factors, including several known agents of stress response, mediators of epigenetic changes, regulators of alternative splicing, RNA editing, protein synthesis and folding and proteolytic systems. All these factors are important in cardiovascular function and most of them regulate miRNA biogenesis, but their influence on miRNAs was shown for non-cardiac cells or some specific cardiac pathologies. Finally, we consider that studying the stress response factors, which are upstream regulators of miRNA biogenesis, in the diseased heart could help in (1) explaining some contradictions concerning miRNAs in heart pathology, (2) making the role of miRNAs in pathogenesis of cardiovascular disease more clear, and therefore, (3) getting powerful targets for its molecular therapy.

• MeSH
• biologické modely MeSH
• epigeneze genetická MeSH
• fyziologický stres genetika   MeSH
• kardiovaskulární nemoci genetika   MeSH
• lidé MeSH
• mikro RNA biosyntéza   genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Adipose tissue is an abundant source of autologous adult stem cells that may bring new therapeutic perspectives on the treatment of diabetes and its complications. It is unclear whether adipose tissue-derived stromal cells (ASCs) of diabetic patients, constantly influenced by hyperglycaemia, have the same properties as non-diabetic controls. As an alternative source of ASCs, adipose tissue from distal limbs of diabetic patients with critical ischemia was isolated. ASCs were characterized in terms of cell surface markers, multilineage differentiation and the expression of vascular endothelial growth factor (VEGFA), chemokine-related genes and compared with non-diabetic controls. Flow cytometry analysis confirmed mesenchymal phenotypes in both diabetic and non-diabetic ASCs. Nevertheless, 40% of diabetic and 20% of non-diabetic ASC samples displayed high expressions of fibroblast marker, which inversely correlated with the expression of CD105. In diabetic patients, significantly decreased expression of VEGFA and chemokine receptor CXCR4 was found in fibroblast-positive ASCs, compared with their fibroblast-negative counterparts. Reduced osteogenic differentiation and the downregulation of chemokine CXCL12 were found in fibroblast-negative diabetic ASCs. Both diabetic and non-diabetic ASCs were differentiated into adipocytes and chondrocytes and did not reveal islet-like cell differentiation. According to this study, adipose tissue from distal limbs of diabetic patients is not satisfactory as an autologous ASC source. Hyperglycaemic milieu as well as other metabolic disorders linked to diabetes may have an influence on endogenous stem cell properties. The present study investigated the feasibility of autologous stem cell therapy in diabetic patients. ASCs isolated from the ischemic limb of diabetic patients were found to be less potent when compared phenotypically and functionally to control non-diabetic counterparts with no signs of limb ischemia. High expression of fibroblast markers associated with reduced expression of VEGFA as well as reduced osteogenic differentiation may have an impact on the effectiveness of autologous cell therapies in diabetic patients.

• MeSH
• biologické markery metabolismus   MeSH
• buněčná diferenciace MeSH
• buňky stromatu cytologie   metabolismus   MeSH
• CD antigeny metabolismus   MeSH
• chondrocyty cytologie   metabolismus   MeSH
• cytokiny metabolismus   MeSH
• diabetes mellitus patologie   MeSH
• diabetická noha patologie   MeSH
• dospělí MeSH
• fibroblasty cytologie   metabolismus   MeSH
• ischemie patologie   MeSH
• končetiny krevní zásobení   patologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mezenchymální kmenové buňky cytologie   metabolismus   MeSH
• osteoblasty cytologie   metabolismus   MeSH
• podkožní tuk cytologie   MeSH
• receptory buněčného povrchu metabolismus   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• studie případů a kontrol MeSH
• tukové buňky cytologie   metabolismus   MeSH
• vaskulární endoteliální růstový faktor A metabolismus   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Alzheimer's disease (AD) is accompanied by oxidative stress in the brain. Because the brain tissue is rich in polyunsaturated fatty acids, it is prone to the free radical attack resulting in lipid peroxidation. Intermediates of lipid peroxidation may diffuse from the primary site, cross the blood-brain barrier and modify erythrocyte membranes in the bloodstream. We exposed isolated erythrocyte membranes from patients with AD and the control group to in vitro free radical damage and monitored the accumulation of the end products of lipid peroxidation, lipofuscin-like pigments (LFPs), by fluorescence spectroscopy. LFPs were analyzed by means of tridimensional and synchronous fluorescence spectroscopy. The levels of LFP formed during in vitro peroxidation were significantly higher in erythrocyte membranes from patients with AD compared with the control group. Furthermore, the chemical composition of LFP in AD was different from the control group. The analysis of the specific modifications of erythrocyte membranes in AD is of great medical importance regarding the need of a diagnostic blood biomarker.

• MeSH
• Alzheimerova nemoc metabolismus   MeSH
• erytrocytární membrána metabolismus   MeSH
• lidé MeSH
• lipofuscin metabolismus   MeSH
• oxidační stres MeSH
• peroxidace lipidů MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• studie případů a kontrol MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

We have examined the effect of suberoylanilide hydroxamic acid (SAHA, Vorinostat, Zolinza) on the viability of normal peripheral blood lymphocytes (PBLs) in vitro and on the expression of 20 apoptosis-related genes. RT-PCR, western blots and flow cytometry were performed to reveal the proteins of apoptosis machinery that were affected to cause cell death. Our data suggest that PBL markedly resisted for approximately 24 h the destructive activity of the agent, but eventually 60% of cells treated with 4 micromol/L SAHA died within 72 h through mitochondrial way of apoptosis. While the expression of the majority of genes remained indifferent against 4 micromol/L SAHA, the cellular levels of BimEL, Bmf-2, Bcl-w and survivin mRNA varied, confirming the pro-apoptotic response of SAHA treated PBL. In addition, the expression of multifunctional proteins c-Myc and p21(WAF1) changed profoundly with the time of SAHA treatment. The Bax activator BimEL increased rapidly, driving cells towards apoptosis likely controlled by c-Myc and p21(WAF1) activities. We suggest that variations in c-Myc and p21(WAF1) expression decelerate the apoptosis in the early period and increase the resistance of resting PBL against SAHA. 2009 John Wiley & Sons, Ltd.

• MeSH
• aktivace enzymů účinky léků   MeSH
• buněčná membrána metabolismus   účinky léků   MeSH
• buněčná smrt účinky léků   MeSH
• cytochromy c metabolismus   MeSH
• cytoprotekce účinky léků   MeSH
• financování organizované MeSH
• fosfatidylseriny metabolismus   MeSH
• inhibitor p21 cyklin-dependentní kinasy metabolismus   MeSH
• kaspasy metabolismus   MeSH
• kyseliny hydroxamové farmakologie   MeSH
• lidé MeSH
• lymfocyty cytologie   enzymologie   metabolismus   účinky léků   MeSH
• membránové proteiny metabolismus   MeSH
• membránový potenciál mitochondrií účinky léků   MeSH
• mitochondrie metabolismus   účinky léků   MeSH
• poly(ADP-ribosa)-polymerasy metabolismus   MeSH
• proteiny regulující apoptózu metabolismus   MeSH
• protoonkogenní proteiny c-myc metabolismus   MeSH
• protoonkogenní proteiny metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• regulace genové exprese účinky léků   MeSH
• transport proteinů účinky léků   MeSH
• viabilita buněk účinky léků   MeSH
• Check Tag
• lidé MeSH

CYP2D6 is a member of cytochrome P450 enzymes that metabolise over 25% of commonly used drugs. Genetic polymorphisms can cause insufficient drug efficacy at usually administered doses or can be the cause of adverse drug reaction. CYP2D6 genotyping can be used to predict CYP2D6 phenotype and thereby explain some abnormalities in drug response and thus optimize pharmacotherapy. The aim of this study was to investigate the frequency of functionally important variant alleles of the CYP2D6 gene throughout the Czech population to predict the prevalence of ultra-rapid and poor metabolizer phenotypes. The DNA of 223 unrelated, healthy volunteers was analysed to detect the presence of CYP2D6*6, *5, *4, *3 and gene duplication. The variant allele frequencies in our population were 0.22%, 3.14%, 22.87%, 1.12% and 3.14% for CYP2D6*6, CYP2D6*5, CYP2D6*4, CYP2D6*3 and CYP2D6*MxN, respectively. Fifteen subjects carried two variant alleles leading to predicted poor type of metabolism, 84 subjects were heterozygous extensive metabolizers (het-EM). The full-text contains detailed comparison with European white populations. The distribution of variant alleles complies with the Hardy-Weinberg equilibrium. The frequencies of functional variant alleles of CYP2D6 in Czech population are in concordance with other Caucasian populations. 2007 John Wiley & Sons, Ltd.

• MeSH
• cytochrom P-450 CYP2D6 fyziologie   genetika   MeSH
• dospělí MeSH
• farmakogenetika MeSH
• frekvence genu MeSH
• genotyp MeSH
• jednonukleotidový polymorfismus MeSH
• léčivé přípravky metabolismus   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• populační genetika MeSH
• senioři MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH

Several studies report that hypoxic exposure induces free radical oxidative damage in various tissues. The mechanism of this damage includes membrane lipid peroxidation which can be easily detected by measuring fluorescent end-products of the process, i.e. lipofuscin-like pigments. Four day exposure of rats to hypoxia (10% O(2)) increased the level of lipofuscin-like pigments in erythrocytes up to 9 fold. This increase was completely prevented when the animals were exposed to hypercapnia (4.3% CO(2)) in addition to hypoxia. We studied the possible mechanism of the hypercapnic protection on isolated erythrocyte membranes in vitro. Lipid peroxidation was initiated by incubation of the membranes with iron ions and ascorbate. Production of malonaldehyde, the precursor of lipofuscin-like pigments, was strongly inhibited in bicarbonate buffer. Similarly the production of lipofuscin-like products was damped. These experiments suggest that the protective effect of hypercapnia might consist in direct interaction of CO(2) with free radical processes. Copyright (c) 2008 John Wiley & Sons, Ltd.

• MeSH
• časové faktory MeSH
• cytoprotekce MeSH
• erytrocytární membrána metabolismus   MeSH
• erytrocyty cytologie   metabolismus   MeSH
• fluorescenční spektrometrie MeSH
• hyperkapnie metabolismus   MeSH
• hypoxie metabolismus   MeSH
• krysa rodu rattus MeSH
• lipofuscin biosyntéza   MeSH
• luminiscence MeSH
• luminol metabolismus   MeSH
• malondialdehyd metabolismus   MeSH
• peroxidace lipidů MeSH
• potkani Wistar MeSH
• volné radikály metabolismus   MeSH
• železo metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• práce podpořená grantem MeSH

The molecular mechanisms involved in GPCR-initiated signaling cascades where the two receptors share the same signaling cascade, such as thyrotropin-releasing hormone (TRH) and angiotensin II (ANG II), are still far from being understood. Here, we analyzed hormone-induced Ca(2+) responses and the process of desensitization in HEK-293 cells, which express endogenous ANG II receptors. These cells were transfected to express exogenously high levels of TRH receptors (clone E2) or both TRH receptors and G(11)alpha protein (clone E2M11). We observed that the characteristics of the Ca(2+) response, as well as the process of desensitization, were both strongly dependent on receptor number and G(11)alpha protein level. Whereas treatment of E2 cells with TRH or ANG II led to significant desensitization of the Ca(2+) response to subsequent addition of either hormone, the response was not desensitized in E2M11 cells expressing high levels of G(11)alpha. In addition, stimulation of both cell lines with THR elicited a clear heterologous desensitization to subsequent stimulation with ANG II. On the other hand, ANG II did not affect a subsequent response to TRH. ANG II-mediated signal transduction was strongly dependent on plasma membrane integrity modified by cholesterol depletion, but signaling through TRH receptors was altered only slightly under these conditions. It may be concluded that the level of expression of G-protein-coupled receptors and their cognate G-proteins strongly influences not only the magnitude of the Ca(2+) response but also the process of desensitization and resistance to subsequent hormone addition.

• MeSH
• angiotensin II farmakologie   MeSH
• buněčná membrána metabolismus   účinky léků   MeSH
• časové faktory MeSH
• cholesterol analýza   metabolismus   MeSH
• financování organizované MeSH
• hormon uvolňující thyreotropin farmakologie   MeSH
• kultivované buňky MeSH
• lidé MeSH
• proteiny vázající GTP - alfa-podjednotky Gq-G11 biosyntéza   genetika   účinky léků   MeSH
• receptory thyroliberinu biosyntéza   účinky léků   MeSH
• teplota MeSH
• transfekce MeSH
• vápník farmakologie   metabolismus   MeSH
• vápníková signalizace fyziologie   účinky léků   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• Check Tag
• lidé MeSH

We have examined the effect of sodium butyrate (SB) on the viability of normal peripheral blood lymphocytes (PBLs) in vitro and the effect of this agent on the expression of 20 apoptosis-related genes. Data suggest that PBL treated with 2 mmol L(-1) SB resisted for at least 8 h the destructive activity of the agent, but eventually 30% of cells died within 72 h. As documented by flow cytometry and cytochrome c release study, cells underwent mitochondrial-derived apoptosis. While the expression of the majority of genes examined by RT-PCR and Western blots remained indifferent to 2 mmol L(-1) SB, the cellular levels of BimEL, c-myc, p53, and p21(WAF1) varied profoundly with the time of SB treatment. The Bax activator BimEL increased rapidly, driving cells toward apoptosis likely controlled by c-myc and p21(WAF1) activities. The c-myc, exercising the role of mediator of the function of BimEL and inhibitor of p21(WAF1) expression, decreased significantly for several hours after adding SB but within 48 h it returned to close to its original value. An apoptosis inhibitor and executive caspase substrate p21(WAF1) increased early at the beginning of treatment but subsequently, within a time frame of 72 h, profoundly dropped in terms of both a caspase-dependent and caspase-independent way. We suggest that variations in c-myc and p21(WAF1) expression delay apoptosis making PBL resistant to SB for several hours, and together with fast catabolism of SB in vivo protect PBL against the destructive activity of this anti-cancerous metabolite of colonic bacteria. (c) 2008 John Wiley & Sons, Ltd.

• MeSH
• aktivace enzymů MeSH
• apoptóza účinky léků   MeSH
• cytochromy c metabolismus   sekrece   MeSH
• financování organizované MeSH
• inhibitor p21 cyklin-dependentní kinasy genetika   metabolismus   MeSH
• intracelulární membrány účinky léků   MeSH
• kaspasy metabolismus   MeSH
• kolagen typ XI metabolismus   MeSH
• kultivované buňky MeSH
• kyselina máselná farmakologie   MeSH
• lidé MeSH
• lymfocyty metabolismus   sekrece   účinky léků   MeSH
• membránové proteiny genetika   metabolismus   MeSH
• mitochondrie účinky léků   MeSH
• proteiny regulující apoptózu genetika   metabolismus   MeSH
• protoonkogenní proteiny c-myc genetika   metabolismus   MeSH
• protoonkogenní proteiny genetika   metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• regulace genové exprese účinky léků   MeSH
• Check Tag
• lidé MeSH

Reactive oxygen species are known to increase in plant senescence. We investigated the participation of antioxidative enzymes in initiation of cotyledon senescence. Senescence of bean (Phaseolus vulgaris L.) cotyledons was modulated by UV C irradiation and by the decapitation of plant apices. Senescence was accompanied by a decrease of protein content and by a decrease of photochemical efficiency. A drop in activity of antioxidative enzymes preceded the onset of senescence in control plants. In cotyledons with prolonged life span, the decrease of antioxidant activities and the markers of senescence onset appeared at a similar age as in controls. Thus we presumed that the period from senescence initiation to cotyledon abscission was extended. On the other hand, in UV C irradiated plants we did not observe actual senescence initiation, and antioxidant enzymes although elevated, did not effectively play their role. The decrease of antioxidant enzymes activity and the markers of senescence appeared at a similar age both in control and in decapitated (D) plants, so we can presume that we prolonged mainly the period from senescence onset to cotyledon abscission in D plants. In UV C irradiated plants the antioxidative enzymes were probably destroyed before the process of senescence could begin. 2005 John Wiley & Sons, Ltd.

• MeSH
• antioxidancia metabolismus   MeSH
• fazol metabolismus   růst a vývoj   MeSH
• financování organizované MeSH
• glutathionreduktasa metabolismus   MeSH
• izoenzymy metabolismus   MeSH
• katalasa metabolismus   MeSH
• peroxidasy metabolismus   MeSH
• rozpustnost MeSH
• superoxiddismutasa metabolismus   MeSH

Both oxidants and antioxidants have been shown to modulate cell proliferation. We studied the effects of hydrogen peroxide and two antioxidants on the rate of proliferation of lens epithelial cells in culture. Hydrogen peroxide at concentrations higher than 32 microM caused a significant inhibition of proliferation. However, in the concentration range of 0.01-0.5 microM, hydrogen peroxide stimulated the rate of proliferation. The effect of hydrogen peroxide was dependent on the amount of cells in an individual culture well, indicating decomposition of hydrogen peroxide by cellular enzymes. In order to eliminate the possibility of decomposition of the dose of hydrogen peroxide given as a bolus, we induced continual production of hydrogen peroxide by adding glucose oxidase to the incubation medium. We found that hydrogen peroxide, generated by 1-50 microU x ml(-1) of glucose oxidase significantly increased the rate of cell proliferation. This effect was most apparent at the beginning of the exponential phase of cellular growth. Glucose oxidase alone (100-500 microU x ml(-1)) did not produce any effect. The effects of pro-oxidative hydrogen peroxide were compared with the effects of two biologically important antioxidants, alpha-tocopherol and retinol. Both antioxidants completely inhibited proliferation at concentrations of 30 microM and higher. In contrast to retinol, the effect of alpha-tocopherol was dependent on the amount of cells, indicating cellular decomposition of alpha-tocopherol. The results document the possibility of redox regulation of cellular proliferation at physiologically relevant reactant concentrations. Copyright (c) 2006 John Wiley & Sons, Ltd.

• MeSH
• alfa-tokoferol farmakologie   MeSH
• anilidy MeSH
• antioxidancia farmakologie   MeSH
• azosloučeniny MeSH
• epitelové buňky metabolismus   účinky léků   MeSH
• financování organizované MeSH
• králíci MeSH
• kultivované buňky MeSH
• oční čočka cytologie   MeSH
• oxidancia farmakologie   MeSH
• peroxid vodíku farmakologie   MeSH
• počet buněk MeSH
• proliferace buněk účinky léků   MeSH
• vitamin A farmakologie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• zvířata MeSH