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1.
Endocr Pathol ; 35(1): 14-24, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38416360

RESUMO

Hand2 is a core transcription factor responsible for chromaffin cell differentiation. However, its potential utility in surgical pathology has not been studied. Thus, we aimed to investigate its expression in paragangliomas, other neuroendocrine neoplasms (NENs), and additional non-neuroendocrine tumors. We calibrated Hand2 immunohistochemistry on adrenal medulla cells and analyzed H-scores in 46 paragangliomas (PGs), 9 metastatic PGs, 21 cauda equina neuroendocrine tumors (CENETs), 48 neuroendocrine carcinomas (NECs), 8 olfactory neuroblastomas (ONBs), 110 well-differentiated NETs (WDNETs), 10 adrenal cortical carcinomas, 29 adrenal cortical adenomas, 8 melanomas, 41 different carcinomas, and 10 gastrointestinal stromal tumors (GISTs). Both tissue microarrays (TMAs) and whole sections (WSs) were studied. In 171 NENs, previously published data on Phox2B and GATA3 were correlated with Hand2. Hand2 was positive in 98.1% (54/55) PGs, but only rarely in WDNETs (9.6%, 10/104), CENETs (9.5%, 2/21), NECs (4.2%, 2/48), or ONBs (12.5%, 1/8). Any Hand2 positivity was 98.1% sensitive and 91.7% specific for the diagnosis of PG. The Hand2 H-score was significantly higher in primary PGs compared to Hand2-positive WDNETs (median 166.3 vs. 7.5; p < 0.0001). Metastatic PGs were positive in 88.9% (8/9). No Hand2 positivity was observed in any adrenal cortical neoplasm or other non-neuroendocrine tumors, with exception of 8/10 GISTs. Parasympathetic PGs showed a higher Hand2 H-score compared to sympathetic PGs (median H-scores 280 vs. 104, p < 0.0001). Hand2 positivity in NENs serves as a reliable marker of primary and metastatic PG, since other NENs only rarely exhibit limited Hand2 positivity.


Assuntos
Carcinoma Neuroendócrino , Tumores Neuroendócrinos , Paraganglioma , Humanos , Imuno-Histoquímica , Tumores Neuroendócrinos/patologia , Fatores de Transcrição/metabolismo , Paraganglioma/diagnóstico , Paraganglioma/patologia , Carcinoma Neuroendócrino/patologia
2.
Int J Mol Sci ; 22(5)2021 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-33802468

RESUMO

According to the World Health Organization, cardiovascular diseases are the main cause of death worldwide. They may be caused by various factors or combinations of factors. Frequently, endothelial dysfunction is involved in either development of the disorder or results from it. On the other hand, the endothelium may be disordered for other reasons, e.g., due to infection, such as COVID-19. The understanding of the role and significance of the endothelium in the body has changed significantly over time-from a simple physical barrier to a complex system encompassing local and systemic regulation of numerous processes in the body. Endothelium disorders may arise from impairment of one or more signaling pathways affecting dilator or constrictor activity, including nitric oxide-cyclic guanosine monophosphate activation, prostacyclin-cyclic adenosine monophosphate activation, phosphodiesterase inhibition, and potassium channel activation or intracellular calcium level inhibition. In this review, plants are summarized as sources of biologically active substances affecting the endothelium. This paper compares individual substances and mechanisms that are known to affect the endothelium, and which subsequently may cause the development of cardiovascular disorders.


Assuntos
Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiologia , Plantas/química , Metabolismo Secundário , Endotélio Vascular/citologia , Humanos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Plantas/metabolismo , Vasodilatação/efeitos dos fármacos , Vasodilatação/fisiologia , Vasodilatadores/química , Vasodilatadores/farmacologia
3.
Biochem Pharmacol ; 171: 113695, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31706846

RESUMO

Several papers have reported that calcium channel blocking drugs were associated with increased breast cancer risk and worsened prognosis. One of the most common signs of breast tumors is the presence of small deposits of calcium, known as microcalcifications. Therefore, we studied the effect of dihydropyridine nifedipine on selected calcium transport systems in MDA-MB-231 cells, originating from triple negative breast tumor and JIMT1 cells that represent a model of HER2-positive breast cancer, which possesses amplification of HER2 receptor, but cells do not response to HER2 inhibition treatment with trastuzumab. Also, we compared the effect of nifedipine on colorectal DLD1 and ovarian A2780 cancer cells. Both, inositol 1,4,5-trisphosphate receptor type 1 (IP3R1) and type 1 sodium calcium exchanger (NCX1) were upregulated due to nifedipine in DLD1 and A2780 cells, but not in breast cancer MDA-MB-231 and JIMT1 cells. On contrary to MDA-MB-231 and JIMT1 cells, in DLD1 and A2780 cells nifedipine induced apoptosis in a concentration-dependent manner. After NCX1 silencing and subsequent treatment with nifedipine, proliferation was decreased in MDA-MB-231, increased in DLD1 cells, and not changed in JIMT1 cells. Silencing of IP3R1 revealed increase in proliferation in DLD1 and JIMT1 cells, but caused decrease in proliferation in MDA-MB-231 cell line after nifedipine treatment. Interestingly, after nifedipine treatment migration was not significantly affected in any of tested cell lines after NCX1 silencing. Due to IP3R1 silencing, significant decrease in migration occurred in MDA-MB-231 cells after nifedipine treatment, but not in other tested cells. These results support different function of the NCX1 and IP3R1 in the invasiveness of various cancer cells due to nifedipine treatment.


Assuntos
Sinalização do Cálcio/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Nifedipino/farmacologia , Antineoplásicos Imunológicos/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/genética , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Bloqueadores dos Canais de Cálcio/farmacologia , Sinalização do Cálcio/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Receptores de Inositol 1,4,5-Trifosfato/genética , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Interferência de RNA , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo , Trocador de Sódio e Cálcio/genética , Trocador de Sódio e Cálcio/metabolismo , Trastuzumab/farmacologia , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologia
4.
Eur J Gastroenterol Hepatol ; 30(11): 1297-1303, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30134383

RESUMO

BACKGROUND: Serum vitamin D level is commonly low in patients with inflammatory bowel disease (IBD). Although there is a growing body of evidence that links low vitamin D level to certain aspects of IBD such as disease activity and quality of life, data on its prevalence and how it varies across disease phenotype, smoking status and treatment groups are still missing. MATERIALS AND METHODS: Patients diagnosed with IBD between 2010 and 2011 were recruited. Demographic data and serum vitamin D levels were collected. Variance of vitamin D level was then assessed across different treatment groups, disease phenotype, disease activity and quality of life scores. RESULTS: A total of 238 (55.9% male) patients were included. Overall, 79% of the patients had either insufficient or deficient levels of vitamin D at diagnosis. Patients needing corticosteroid treatment at 1 year had significantly lower vitamin D levels at diagnosis (median 36.0 nmol/l) (P=0.035). Harvey-Bradshaw Index (P=0.0001) and Simple Clinical Colitis Activity Index scores (P=0.0001) were significantly lower in patients with higher vitamin D level. Serum vitamin D level correlated significantly with SIBQ score (P=0.0001) and with multiple components of SF12. Smokers at diagnosis had the lowest vitamin D levels (vitamin D: 34 nmol/l; P=0.053). CONCLUSION: This study demonstrates the high prevalence of low vitamin D levels in treatment-naive European IBD populations. Furthermore, it demonstrates the presence of low vitamin D levels in patients with IBD who smoke.


Assuntos
Doenças Inflamatórias Intestinais/epidemiologia , Deficiência de Vitamina D/epidemiologia , Adolescente , Corticosteroides/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Anti-Inflamatórios/uso terapêutico , Biomarcadores/sangue , Criança , Europa (Continente)/epidemiologia , Feminino , Humanos , Doenças Inflamatórias Intestinais/diagnóstico , Doenças Inflamatórias Intestinais/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Prevalência , Qualidade de Vida , Fatores de Risco , Índice de Gravidade de Doença , Fumar/efeitos adversos , Fumar/sangue , Fumar/epidemiologia , Fatores de Tempo , Vitamina D/sangue , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/diagnóstico , Adulto Jovem
5.
Cell Mol Neurobiol ; 38(1): 181-194, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28786032

RESUMO

Haloperidol is an antipsychotic agent that primarily acts as an antagonist of D2 dopamine receptors. Besides other receptor systems, it targets sigma 1 receptors (σ1Rs) and inositol 1,4,5-trisphosphate receptors (IP3Rs). Aim of this work was to investigate possible changes in IP3Rs and σ1Rs resulting from haloperidol treatment and to propose physiological consequences in differentiated NG-108 cells, i.e., effect on cellular plasticity. Haloperidol treatment resulted in up-regulation of both type 1 IP3Rs (IP3R1s) and σ1Rs at mRNA and protein levels. Haloperidol treatment did not alter expression of other types of IP3Rs. Calcium release from endoplasmic reticulum (ER) mediated by increased amount of IP3R1s elevated cytosolic calcium and generated ER stress. IP3R1s were bound to σ1Rs, and translocation of this complex from ER to nucleus occurred in the group of cells treated with haloperidol, which was followed by increased nuclear calcium levels. Haloperidol-induced changes in cytosolic, reticular, and nuclear calcium levels were similar when specific σ1 blocker -BD 1047- was used. Changes in calcium levels in nucleus, ER, and cytoplasm might be responsible for alterations in cellular plasticity, because length of neurites increased and number of neurites decreased in haloperidol-treated differentiated NG-108 cells.


Assuntos
Antipsicóticos/farmacologia , Diferenciação Celular/efeitos dos fármacos , Haloperidol/farmacologia , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Plasticidade Neuronal/efeitos dos fármacos , Receptores sigma/metabolismo , Animais , Diferenciação Celular/fisiologia , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Camundongos , Plasticidade Neuronal/fisiologia , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/fisiologia , Ratos , Receptor Sigma-1
6.
Prostate ; 77(6): 604-616, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28101932

RESUMO

BACKGROUND: Failure in intracellular zinc accumulation is a key process in prostate carcinogenesis. Nevertheless, epidemiological studies of zinc administration have provided contradicting results. In order to examine the impact of the artificial intracellular increase of zinc(II) ions on prostate cancer metabolism, PNT1A, 22Rv1, and PC-3 prostatic cell lines-depicting different stages of cancer progression-and their zinc-resistant counterparts were used. To determine "benign" and "malignant" metabolic profiles, amino acid patterns, gene expression, and antioxidant capacity of these cell lines were assessed. METHODS: Amino acid profiles were examined using an ion-exchange liquid chromatography. Intracellular zinc content was measured by atomic absorption spectrometry. Metallothionein was quantified using differential pulse voltammetry. The content of reduced glutathione was determined using high performance liquid chromatography coupled with an electrochemical detector. Cellular antioxidant capacity was determined by the ABTS test and gene expression analysis was performed by qRT-PCR. RESULTS AND CONCLUSIONS: Long-term zinc treatment was shown to reroute cell metabolism from benign to more malignant type. Long-term application of high concentration of zinc(II) significantly enhanced cisplatin resistance, invasiveness, cellular antioxidant capacity, synthesis of glutathione, and expression of treatment resistance- and stemness-associated genes (SOX2, POU5F1, BIRC5). Tumorous cell lines universally displayed high accumulation of aspartate and sarcosine and depletion of essential amino acids. Increased aspartate/threonine, aspartate/methionine, and sarcosine/serine ratios were associated with cancer phenotype with high levels of sensitivity and specificity. Prostate 77: 604-616, 2017. © 2017 Wiley Periodicals, Inc.


Assuntos
Aminoácidos/genética , Progressão da Doença , Resistencia a Medicamentos Antineoplásicos/genética , Perfilação da Expressão Gênica/métodos , Neoplasias da Próstata/genética , Zinco/farmacologia , Adulto , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Movimento Celular/fisiologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Humanos , Masculino , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia , Zinco/uso terapêutico
7.
Curr Drug Metab ; 18(3): 237-263, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28059036

RESUMO

BACKGROUND: Anthracycline antibiotic doxorubicin (DOX) is a very potent and extensively prescribed chemotherapeutic drug. It is widely utilized in the therapy of variety of haematological and solid tumours, although its administration is commonly accompanied with several severe side effects. The most serious one is a development of dose-dependent and cumulative cardiotoxicity. In the course of time, many strategies have been investigated in order to avoid or at least to diminish DOX-induced cardiac dysfunction; these include reduction of toxic effect by coadministration with iron chelators (dexrazoxane), trastuzumab, taxanes, statins, and ACE-inhibitors. However, the attenuation of cardiotoxic effect is still not satisfactory yet. OBJECTIVE: This review represents an overall appraisal of studies concerning with the utilization of various doxorubicinloaded nanoparticles in the cancer treatment with specific emphasis on those studies evaluating their influence on the reduction of heart tissue damage. CONCLUSION: Introduction of nanoscale drug delivery systems undoubtedly represents nowadays one of the most promising tools for lowering systemic toxicity. Nanoparticles enable to target the therapeutic payload directly towards the tumor tissue, thus leading to the increased accumulation of the drug in the desired tissue and simultaneously protecting surrounding healthy tissues.


Assuntos
Antibióticos Antineoplásicos/administração & dosagem , Antibióticos Antineoplásicos/efeitos adversos , Cardiotoxicidade/prevenção & controle , Doxorrubicina/administração & dosagem , Doxorrubicina/efeitos adversos , Animais , Cardiotoxicidade/diagnóstico , Portadores de Fármacos/administração & dosagem , Humanos , Nanopartículas/administração & dosagem , Neoplasias/tratamento farmacológico
8.
Oncotarget ; 7(38): 61403-61418, 2016 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-27528021

RESUMO

In this study we show that anti-tumor effect of sulforaphane (SFN) is partially realized through the type 1 inositol 1,4,5-trisphosphate receptor (IP3R1). This effect was verified in vitro on three different stable cell lines and also in vivo on the model of nude mice with developed tumors. Early response (6 hours) of A2780 ovarian carcinoma cells to SFN treatment involves generation of mitochondrial ROS and increased transcription of NRF2 and its downstream regulated genes including heme oxygenase 1, NAD(P)H:quinine oxidoreductase 1, and KLF9. Prolonged SFN treatment (24 hours) upregulated expression of NRF2 and IP3R1. SFN induces a time-dependent phosphorylation wave of HSP27. Use of IP3R inhibitor Xestospongin C (Xest) attenuates both SFN-induced apoptosis and the level of NRF2 protein expression. In addition, Xest partially attenuates anti-tumor effect of SFN in vivo. SFN-induced apoptosis is completely inhibited by silencing of IP3R1 gene but only partially blocked by silencing of NRF2; silencing of IP3R2 and IP3R3 had no effect on these cells. Xest inhibitor does not significantly modify SFN-induced increase in the rapid activity of ARE and AP1 responsive elements. We found that Xest effectively reverses the SFN-dependent increase of nuclear content and decrease of reticular calcium content. In addition, immunofluorescent staining with IP3R1 antibody revealed that SFN treatment induces translocation of IP3R1 to the nucleus. Our results clearly show that IP3R1 is involved in SFN-induced apoptosis through the depletion of reticular calcium and modulation of transcription factors through nuclear calcium up-regulation.


Assuntos
Anticarcinógenos/farmacologia , Apoptose/efeitos dos fármacos , Cálcio/metabolismo , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Isotiocianatos/farmacologia , Fator 2 Relacionado a NF-E2/metabolismo , Animais , Anticarcinógenos/uso terapêutico , Elementos de Resposta Antioxidante , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Retículo Endoplasmático/metabolismo , Feminino , Heme Oxigenase-1/metabolismo , Humanos , Receptores de Inositol 1,4,5-Trifosfato/antagonistas & inibidores , Isotiocianatos/uso terapêutico , Fatores de Transcrição Kruppel-Like/metabolismo , Compostos Macrocíclicos/farmacologia , Camundongos , Camundongos Nus , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , NAD(P)H Desidrogenase (Quinona)/metabolismo , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/patologia , Oxazóis/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Sulfóxidos , Ativação Transcricional/efeitos dos fármacos , Regulação para Cima , Ensaios Antitumorais Modelo de Xenoenxerto
9.
Gen Physiol Biophys ; 35(1): 13-23, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26612918

RESUMO

Calcium plays a crucial role in numerous processes in living systems, from both intracellular and intercellular signalling to blood clotting. Calcium can be replaced by strontium in various intracellular processes due to high level of their similarity and strontium thus may serve as a valuable tool for different experimental studies. On the other hand, strontium is also used in clinical medicine and is commonly taken to the human body with food and water. The negative cardiac side effects of strontium therapy of osteoporosis and bone metastases are well known, but still not fully explained. This fact explains enhanced interest in this element and its impact on human body. This article reviews effects of calcium and strontium on several biochemical and physiological processes, with special emphasis on cardiac muscle.


Assuntos
Cálcio/metabolismo , Acoplamento Excitação-Contração/fisiologia , Coração/fisiologia , Contração Miocárdica/fisiologia , Miócitos Cardíacos/fisiologia , Estrôncio/metabolismo , Animais , Sinalização do Cálcio/fisiologia , Humanos , Miocárdio/metabolismo
10.
J Atheroscler Thromb ; 20(5): 443-51, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23459505

RESUMO

AIM: The cardio-ankle vascular index (CAVI) is a novel non-invasive marker of arterial stiffness and atherosclerosis. The aim of this work was to examine whether the CAVI value in patients with dyslipidaemia (DLP) is increased by the presence of other cardiovascular risk factors: hypertension, diabetes mellitus, and smoking. METHODS: A total of 392 subjects with DLP (166 male, 226 female), with a median age of 58.5 and 5-95 percentile range 32.2-73.9 years were examined. CAVI was measured using the VaSera 1500 system. RESULTS: CAVI correlated significantly with age (p<0.001) and both systolic (p<0.001) and diastolic (p=0.002) blood pressure; higher values were found in men (p=0.034) than in women in the 56-65 age group. There was no significant difference in CAVI between smokers and non-smokers (p= 0.217) and between subjects with and without diabetes mellitus (p= 0.424). CAVI was significantly higher in subjects with hypertension than in the normotensive group (p<0.001) and in statin-treated subjects than in those without statins (p<0.001); however, CAVI values adjusted for age and sex did not differ significantly between these groups. Adjusted CAVI values were higher only in smokers than in non-smokers (former smokers) (p<0.001). CONCLUSION: The study proves conclusively that the CAVI value in DLP patients is not significantly affected by hypertension and diabetes mellitus, but it is increased by smoking.


Assuntos
Tornozelo/irrigação sanguínea , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/fisiopatologia , Dislipidemias/complicações , Dislipidemias/fisiopatologia , Coração/fisiopatologia , Adulto , Idoso , Aterosclerose/etiologia , Aterosclerose/fisiopatologia , Pressão Sanguínea , Feminino , Humanos , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Rigidez Vascular
11.
J Atheroscler Thromb ; 19(5): 453-61, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22659529

RESUMO

AIM: The cardio-ankle vascular index (CAVI) is a new non-invasive marker of arterial stiffness and atherosclerosis. The purpose of this study was to compare CAVI in patients with heterozygous familial hypercholesterolemia (FH) and in healthy controls. METHODS: 82 FH subjects (27 males, 65 females), aged 53.7±13.6 years without clinical symptoms of cardiovascular diseases and 359 healthy controls (121 males, 238 females), aged 43.9±14.9 years, were examined. CAVI was measured using the system VaSera® 1500. RESULTS: CAVI in FH patients was significantly higher (8.0±1.4) than in healthy subjects (7.5±1.3) p = 0.002; however, age, sex and BMI adjusted CAVI did not differ significantly (p = 0.061) between the FH group (7.5, CI: 7.3; 7.7) and control group (7.7, CI: 7.6; 7.7). CONCLUSION: The study showed no significant difference in CAVI between heterozygous FH and healthy controls.


Assuntos
Índice Tornozelo-Braço , Coração/fisiopatologia , Hiperlipoproteinemia Tipo II/fisiopatologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
12.
Gen Physiol Biophys ; 29(4): 381-9, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21157001

RESUMO

Numerous ligands of sigma receptors are known to prolong the QT interval and therefore cause a variety of arrhythmias. High affinity binding sites for the prototypical sigma ligand haloperidol were found in membranes of cardiac myocytes from adult rats. Activation of sigma 1 receptor leads to a release of calcium from the endoplasmic reticulum that follows increased synthesis of inositol 1,4,5-trisphosphate (IP3). We studied the effect of long-term haloperidol treatment on the expression of sigma 1 receptors, IP3 receptors of type 1 and 2 in the individual parts of the rat heart, in isolated rat cardiomyocytes and in PC12 cells. We have found that prolonged treatment with haloperidol significantly increased mRNA levels of sigma 1 receptors in both atria and ventricles. Sigma 1 receptor's mRNA was increased also in isolated cardiomyocytes. Haloperidol treatment affects the expression of IP3 receptors of type 1 and 2 in cardiac atria, but not in cardiac ventricles. We observed increase in IP3 receptors in differentiated PC12 cells, but not in isolated cardiomyocytes. We propose that this increase might participate in triggering cardiac arrhythmias during haloperidol treatment, which has to be further verified.


Assuntos
Antipsicóticos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Haloperidol/farmacologia , Receptores de Inositol 1,4,5-Trifosfato/genética , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Animais , Átrios do Coração/efeitos dos fármacos , Átrios do Coração/metabolismo , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/metabolismo , Masculino , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Células PC12 , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar
13.
Pflugers Arch ; 456(2): 323-37, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18071747

RESUMO

CA IX is an active transmembrane carbonic anhydrase isoform functionally implicated in cell adhesion and pH control. Human CA IX is strongly induced by hypoxia and frequently associated with various tumors. In this study, we investigated the expression of the rat CA IX in response to chronic hypoxia and to treatment with chemical compounds that disrupt oxygen sensing, including dimethyloxalylglycine, dimethylester succinate, diazoxide, and tempol. We brought the evidence that expression of CA IX is regulated by hypoxia and hypoxia-mimicking compounds in immortalized Rat2 fibroblasts and BP6 rat fibrosarcoma cells in a cell-type-specific manner. We also demonstrated, for the first time, that CA IX is expressed in hypoxic primary rat cardiomyocytes and in immortalized H9c2 cardiomyocytes exposed to physiological or chemical hypoxia and that CA IX expression is increased in hypoxic rat tissues in vivo. Our findings suggest that CA IX expression is not limited to cancer but may be also induced in other pathological situations associated with ischemia or metabolic disturbances leading to activation of the HIF pathway. These data support the view that rats can represent useful model for studies of CA IX as a component of endogenous protection mechanisms associated with hypoxia or perturbed oxygen sensing.


Assuntos
Anidrases Carbônicas/metabolismo , Hipóxia Celular/fisiologia , Fibroblastos/metabolismo , Miócitos Cardíacos/metabolismo , Oxigênio/metabolismo , Aminoácidos Dicarboxílicos/farmacologia , Animais , Antioxidantes/farmacologia , Anidrase Carbônica IX , Anidrases Carbônicas/genética , Linhagem Celular , Linhagem Celular Tumoral , Células Cultivadas , Óxidos N-Cíclicos/farmacologia , Diazóxido/farmacologia , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Masculino , Modelos Animais , Modelos Biológicos , Miócitos Cardíacos/citologia , Miócitos Cardíacos/efeitos dos fármacos , Ratos , Ratos Wistar , Marcadores de Spin
14.
J Exp Bot ; 58(3): 637-49, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17175552

RESUMO

Cytokinins (CKs) are involved in the regulation of plant development including plastid differentiation and function. Partial location of CK biosynthetic pathways in plastids suggests the importance of CKs for chloroplast development. The impact of genetically modified CK metabolism on endogenous CK, indole-3-acetic acid, and abscisic acid contents in leaves and isolated intact chloroplasts of Nicotiana tabacum was determined by liquid chromatography/mass spectrometry and two-dimensional high-performance liquid chromatography, and alterations in chloroplast ultrastructure by electron microscopy. Ectopic expression of Sho, a gene encoding a Petunia hybrida isopentenyltransferase, was employed to raise CK levels. The increase in CK levels was lower in chloroplasts than in leaves. CK levels were reduced in leaves of tobacco harbouring a CK oxidase/dehydrogenase gene, AtCKX3. The total CK content also decreased in chloroplasts, but CK phosphate levels were higher than in the wild type. In a transformant overexpressing a maize beta-glucosidase gene, Zm-p60.1, naturally targeted to plastids, a decrease of CK-O-glucosides in chloroplasts was found. In leaves, the changes were not significant. CK-O-glucosides accumulated to very high levels in leaves, but not in chloroplasts, of plants overexpressing a ZOG1 gene, encoding trans-zeatin-O-glucosyltransferase from Phaseolus lunatus. Manipulation of the CK content affected levels of indole-3-acetic and abscisic acid. Chloroplasts of plants constitutively overexpressing Sho displayed ultrastructural alterations including the occasional occurrence of crystalloids and an increased number of plastoglobuli. The other transformants did not exhibit any major differences in chloroplast ultrastructure. The results suggest that plant hormone compartmentation plays an important role in hormone homeostasis and that chloroplasts are rather independent organelles with respect to regulation of CK metabolism.


Assuntos
Ácido Abscísico/metabolismo , Citocininas/metabolismo , Ácidos Indolacéticos/metabolismo , Nicotiana/genética , Plantas Geneticamente Modificadas/metabolismo , Alquil e Aril Transferases/genética , Alquil e Aril Transferases/metabolismo , Cloroplastos/metabolismo , Cloroplastos/ultraestrutura , Glucosiltransferases/genética , Microscopia Eletrônica de Transmissão , Oxirredutases/genética , Oxirredutases/metabolismo , Petunia/genética , Phaseolus/genética , Folhas de Planta/metabolismo , Folhas de Planta/ultraestrutura , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/ultraestrutura , Nicotiana/metabolismo , Nicotiana/ultraestrutura , Zea mays/genética , beta-Glucosidase/genética , beta-Glucosidase/metabolismo
15.
J Exp Bot ; 57(6): 1413-21, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16556629

RESUMO

Changes in the contents of polyamines (PAs) in tobacco leaves (Nicotiana tabacum L. cv. Wisconsin 38) grown under 16 h photoperiod were correlated with arginine and ornithine decarboxylase (EC 4.1.1.19 and EC 4.1.1.17) and diamine oxidase (EC 1.4.3.6) activities. The maximum of free and soluble conjugated forms of PAs occurred 1-2 h after the middle of the light period and was followed by two distinct peaks at the end of the light and at the beginning of the dark phase. Putrescine was the most abundant and cadaverine the least abundant PA in both free and PCA-soluble forms. However, cadaverine was predominant in PCA-insoluble conjugates, followed by putrescine, spermidine, and spermine. Both arginine and ornithine decarboxylases are involved in putrescine biosynthesis in tobacco leaves. Light dramatically stimulated the activity of ornithine decarboxylase, while no photoinduction of arginine decarboxylase activity was observed. Ornithine decarboxylase was found mainly in the particulate fraction. Only one peak, just after light induction, occurred in the cytosolic fraction, with 35% of the total ornithine decarboxylase activity. By contrast, the total arginine decarboxylase activity was equally divided between the soluble and pellet fractions. A sharp increase in diamine oxidase activity occurred 1 h after exposure to light, concomitant with the light-induced increase in ornithine decarboxylase activity. After a decline, diamine oxidase activity increased again, together with the rise in the amount of free Put. The roles of both conjugation of PAs with hydroxycinnamic acids and oxidative degradation of putrescine in maintaining free PA levels during the 24 h light/dark cycle are discussed. The presented results have shown that the parameters studied here followed rhythmical changes and were not only affected by light.


Assuntos
Amina Oxidase (contendo Cobre)/metabolismo , Carboxiliases/metabolismo , Nicotiana/metabolismo , Ornitina Descarboxilase/metabolismo , Fotoperíodo , Poliaminas/metabolismo , Folhas de Planta/enzimologia , Folhas de Planta/metabolismo , Nicotiana/enzimologia
16.
J Exp Bot ; 56(421): 2877-83, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16157652

RESUMO

As many processes are regulated by both light and plant hormones, evaluation of diurnal variations of their levels may contribute to the elucidation of the complex network of light and hormone signal transduction pathways. Diurnal variation of cytokinin, auxin, and abscisic acid levels was tested in tobacco leaves (Nicotiana tabacum L. cv. Wisconsin 38) grown under a 16/8 h photoperiod. The main peak of physiologically active cytokinins (cytokinin bases and ribosides) was found after 9 h of light, i.e. 1 h after the middle of the light period. This peak coincided with the major auxin peak and was closely followed by a minor peak of abscisic acid. Free abscisic acid started to increase at the light/dark transition and reached its maximum 3 h after dark initiation. The content of total cytokinins (mainly N-glucosides, followed by cis-zeatin derivatives and nucleotides) exhibited the main peak after 9 h of light and the minor peak after the transition to darkness. The main, midday peak of active cytokinins was preceded by a period of minimal metabolic conversion of tritiated trans-zeatin (less than 30%). The major cytokinin-degrading enzyme, cytokinin oxidase/dehydrogenase (EC 1.5.99.12), exhibited maximal activity after the dark/light transition and during the diminishing of the midday cytokinin peak. The former peak might be connected with the elimination of the long-distance cytokinin signal. These cytokinin oxidase/dehydrogenase peaks were accompanied by increased activity of beta-glucosidase (EC 3.2.1.21), which might be involved in the hydrolysis of cytokinin O-glucosides and/or in fine-tuning of active cytokinin levels at their midday peak. The achieved data indicate that cytokinin metabolism is tightly regulated by the circadian clock.


Assuntos
Ácido Abscísico/metabolismo , Ritmo Circadiano/fisiologia , Citocininas/metabolismo , Ácidos Indolacéticos/metabolismo , Nicotiana/metabolismo , Folhas de Planta/metabolismo , Regulação da Expressão Gênica de Plantas , Glucosídeos/metabolismo , Oxirredutases/metabolismo , Nicotiana/enzimologia , Nicotiana/genética , Zeatina/metabolismo , beta-Glucosidase/metabolismo
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