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1.
Int J Mol Sci ; 25(11)2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38892309

RESUMO

The sodium pump, or Na+/K+-ATPase (NKA), is an essential enzyme found in the plasma membrane of all animal cells. Its primary role is to transport sodium (Na+) and potassium (K+) ions across the cell membrane, using energy from ATP hydrolysis. This transport creates and maintains an electrochemical gradient, which is crucial for various cellular processes, including cell volume regulation, electrical excitability, and secondary active transport. Although the role of NKA as a pump was discovered and demonstrated several decades ago, it remains the subject of intense research. Current studies aim to delve deeper into several aspects of this molecular entity, such as describing its structure and mode of operation in atomic detail, understanding its molecular and functional diversity, and examining the consequences of its malfunction due to structural alterations. Additionally, researchers are investigating the effects of various substances that amplify or decrease its pumping activity. Beyond its role as a pump, growing evidence indicates that in various cell types, NKA also functions as a receptor for cardiac glycosides like ouabain. This receptor activity triggers the activation of various signaling pathways, producing significant morphological and physiological effects. In this report, we present the results of a comprehensive review of the most outstanding studies of the past five years. We highlight the progress made regarding this new concept of NKA and the various cardiac glycosides that influence it. Furthermore, we emphasize NKA's role in epithelial physiology, particularly its function as a receptor for cardiac glycosides that trigger intracellular signals regulating cell-cell contacts, proliferation, differentiation, and adhesion. We also analyze the role of NKA ß-subunits as cell adhesion molecules in glia and epithelial cells.


Assuntos
ATPase Trocadora de Sódio-Potássio , ATPase Trocadora de Sódio-Potássio/metabolismo , ATPase Trocadora de Sódio-Potássio/química , Animais , Humanos , Membrana Celular/metabolismo , Transdução de Sinais , Ouabaína/farmacologia , Ouabaína/metabolismo , Glicosídeos Cardíacos/metabolismo , Glicosídeos Cardíacos/farmacologia , Sódio/metabolismo
2.
Int J Mol Sci ; 24(23)2023 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-38069012

RESUMO

Ouabain, a substance originally obtained from plants, is now classified as a hormone because it is produced endogenously in certain animals, including humans. However, its precise effects on the body remain largely unknown. Previous studies have shown that ouabain can influence the phenotype of epithelial cells by affecting the expression of cell-cell molecular components and voltage-gated potassium channels. In this study, we conducted whole-cell clamp assays to determine whether ouabain affects the activity and/or expression of TRPV4 channels. Our findings indicate that ouabain has a statistically significant effect on the density of TRPV4 currents (dITRPV4), with an EC50 of 1.89 nM. Regarding treatment duration, dITRPV4 reaches its peak at around 1 h, followed by a subsequent decline and then a resurgence after 6 h, suggesting a short-term modulatory effect related to on TRPV4 channel activity and a long-term effect related to the promotion of synthesis of new TRPV4 channel units. The enhancement of dITRPV4 induced by ouabain was significantly lower in cells seeded at low density than in cells in a confluent monolayer, indicating that the action of ouabain depends on intercellular contacts. Furthermore, the fact that U73122 and neomycin suppress the effect caused by ouabain in the short term suggests that the short-term induced enhancement of dITRPV4 is due to the depletion of PIP2 stores. In contrast, the fact that the long-term effect is inhibited by PP2, wortmannin, PD, FR18, and IKK16 suggests that cSrc, PI3K, Erk1/2, and NF-kB are among the components included in the signaling pathways.


Assuntos
Ouabaína , Canais de Cátion TRPV , Humanos , Animais , Ouabaína/farmacologia , Canais de Cátion TRPV/genética , Canais de Cátion TRPV/metabolismo , Transdução de Sinais , Células Epiteliais/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo
3.
Physiol Rep ; 11(17): e15820, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37667414

RESUMO

Hypertension is a pandemic nowadays. We aimed to investigate whether chronic undernutrition modifies the response to the antihypertensive drug rostafuroxin in juvenile hypertensive rats. Chronic undernutrition was induced in male rats using a multideficient diet known as the Regional Basic Diet (RBD), mimicking alimentary habits in impoverished regions worldwide. Animals were given RBD-or a control/CTRL normal diet for rodents-from weaning to 90 days, and rostafuroxin (1 mg/kg body mass) was orally administered from day 60 onwards. For the last 2 days, the rats were hosted in metabolic cages to measure food/energy, water, Na+ ingestion, and urinary volume. Rostafuroxin increased food/energy/Na+ intake in CTRL and RBD rats but had opposite effects on Na+ balance (intake minus urinary excretion). The drug normalized the decreased plasma Na+ concentration in RBD rats, increased urinary volume in RBD but not in CTRL, and decreased and increased urinary Na+ concentration in the RBD and CTRL groups, respectively. Rostafuroxin decreased the ouabain-sensitive (Na+ +K+ )ATPase and increased the ouabain-resistant Na+ -ATPase from proximal tubule cells in both groups and normalized the systolic blood pressure in RBD without effect in CTRL rats. We conclude that chronic undernutrition modifies the response of blood pressure and metabolic responses to rostafuroxin.


Assuntos
Hipertensão , Desnutrição , Masculino , Ratos , Animais , Anti-Hipertensivos/farmacologia , Anti-Hipertensivos/uso terapêutico , Ouabaína/farmacologia , Hipertensão/tratamento farmacológico , Adenosina Trifosfatases
4.
J Affect Disord ; 334: 307-316, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37150224

RESUMO

BACKGROUND: Bipolar disorder (BD) is a complex and severe mental disorder that affects 1-3 % of the world population. Studies have suggested the involvement of oxidative stress in the physiopathology of this psychiatry disorder. Folic acid (FA), a vitamin from the B complex, is a nutraceutical that has recently been researched as a possible treatment for BD since folate is reduced in patients with the disorder. The present study aimed to evaluate the effects of lithium (Li) and FA on behavioral changes and oxidative stress parameters in an animal model of mania induced by ouabain (OUA). METHODS: Wistar rats received a single intracerebroventricular (ICV) injection of OUA or artificial cerebrospinal fluid (aCSF). From the day following ICV injection, the rats were treated for seven days with gavage injections of Li (47.5 mg/kg/mL), FA (50 mg/kg/mL), or water (1 mL/kg). On the 7th day after OUA injection, locomotor activity was measured using the open-field test. In addition, the oxidative stress parameters were evaluated in rats' frontal cortex, striatum, and hippocampus. RESULTS: OUA induced mania-like behavior and oxidative stress in rats' brains, but Li could reverse these alterations. FA did not affect behavior parameters; however, it presents an antioxidant effect on the brain structures evaluated. LIMITATIONS: The study was only evaluated male rats and ICV injection is an invasive procedure. CONCLUSION: These results indicate that even though FA has an effect against the oxidative stress induced by OUA, this effect was not strong enough to interfere with behavior parameters.


Assuntos
Antimaníacos , Ouabaína , Masculino , Ratos , Animais , Antimaníacos/farmacologia , Antimaníacos/uso terapêutico , Ouabaína/farmacologia , Mania/tratamento farmacológico , Mania/patologia , Ratos Wistar , Ácido Fólico/farmacologia , Ácido Fólico/uso terapêutico , Modelos Animais de Doenças , Encéfalo , Estresse Oxidativo , Lítio/farmacologia , Comportamento Animal
5.
Acta Cir Bras ; 37(11): e371102, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36629529

RESUMO

PURPOSE: To investigate the role of renal denervation (RDN) on endogenous ouabain (EO) secretion in spontaneously hypertensive rats (SHR). METHODS: Sixteen 12-week-old male SHR were randomly separated into the renal denervation group (RDNX group) and sham operation group (sham group), and eight age-matched Wistar Kyoto rats (WKY) were served as control group. EO concentrations, the Na+- K+-ATPaseactivity, and the expression of Na+-K+-ATPase were assessed. RESULTS: EO levels in serum, kidneys and hypothalamus of sham group were higher than in RDNX group (p < 0.05). Renal Na+-K+-ATPase activity subjected to denervation surgery showed significantly reduction when compared with the sham groups (p < 0.05). A positive correlation existed between norepinephrine (NE) content and Na+-K+-ATPase activity in the kidney (r2 = 0.579). Renal Na+-K+-ATPase α1 subunit mRNA expression was down-regulated in the RDNX group compared with the sham group (P < 0.05), while renal Na+-K+-ATPase α1 subunit mRNA expression was no statistical significance between the groups (P = 0.63). Immunohistochemical analysis showed that there were significant differences in the renal expression of Na+-K+-ATPasebetween the three groups (P < 0.05). CONCLUSIONS: These experiments demonstrate that RDN exerted an anti-hypertensive effect with reduction of EO levels and Na+-K+-ATPase activity and Na+-K+-ATPase α1 subunit expression of kidney in SHR.


Assuntos
Hipertensão , Ouabaína , Ratos , Animais , Masculino , Ratos Endogâmicos SHR , Ouabaína/farmacologia , Ouabaína/metabolismo , Hipertensão/metabolismo , Rim/metabolismo , Ratos Endogâmicos WKY , Sódio , ATPase Trocadora de Sódio-Potássio/metabolismo , Denervação , RNA Mensageiro/metabolismo
6.
Int J Mol Sci ; 23(21)2022 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-36362049

RESUMO

Ouabain is a cardiac glycoside, initially isolated from plants, and currently thought to be a hormone since some mammals synthesize it endogenously. It has been shown that in epithelial cells, it induces changes in properties and components related to apical-basolateral polarity and cell-cell contacts. In this work, we used a whole-cell patch clamp to test whether ouabain affects the properties of the voltage-gated potassium currents (Ik) of epithelial cells (MDCK). We found that: (1) in cells arranged as mature monolayers, ouabain induced changes in the properties of Ik; (2) it also accelerated the recovery of Ik in cells previously trypsinized and re-seeded at confluence; (3) in cell-cell contact-lacking cells, ouabain did not produce a significant change; (4) Na+/K+ ATPase might be the receptor that mediates the effect of ouabain on Ik; (5) the ouabain-induced changes in Ik required the synthesis of new nucleotides and proteins, as well as Golgi processing and exocytosis, as evidenced by treatment with drugs inhibiting those processes; and (5) the signaling cascade included the participation of cSrC, PI3K, Erk1/2, NF-κB and ß-catenin. These results reveal a new role for ouabain as a modulator of the expression of voltage-gated potassium channels, which require cells to be in contact with themselves.


Assuntos
Ouabaína , Canais de Potássio de Abertura Dependente da Tensão da Membrana , Animais , Ouabaína/farmacologia , Potássio/metabolismo , Canais de Potássio/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Células Epiteliais/metabolismo , Mamíferos/metabolismo
7.
Mol Neurobiol ; 59(12): 7170-7181, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36121567

RESUMO

INTRODUCTION: Despite possible risks of mania switching with the long-term use of antidepressants in patients with bipolar disorder (BD), these drugs may help in depressive episodes. Alterations in neurotrophic factor levels seem to be involved in the pathophysiology of BD. The present study aimed to evaluate the effect of acute treatment of imipramine on behavior and neurotrophic levels in rats submitted to the animal model for BD induced by ouabain. METHODS: Wistar rats received a single intracerebroventricular (ICV) injection of artificial cerebrospinal fluid or ouabain (10-3 M). Following the ICV administration, the rats were treated for 14 days with saline (NaCl 0.9%, i.p.), lithium (47.5 mg/kg, i.p.), or valproate (200 mg/kg, i.p.). On the 13th and 14th days of treatment, the animals received an additional injection of saline or imipramine (10 mg/kg, i.p.). Behavior tests were evaluated 7 and 14 days after ICV injection. Adrenal gland weight and concentrations of ACTH were evaluated. Levels of neurotrophins BDNF, NGF, NT-3, and GDNF were measured in the frontal cortex and hippocampus by ELISA test. RESULTS: The administration of ouabain induced mania- and depressive-like behavior in the animals 7 and 14 days after ICV, respectively. The treatment with lithium and valproate reversed the mania-like behavior. All treatments were able to reverse most of the depressive-like behaviors induced by ouabain. Moreover, ouabain increased HPA-axis parameters in serum and decreased the neurotrophin levels in the frontal cortex and hippocampus. All treatments, except imipramine, reversed these alterations. CONCLUSION: It can be suggested that acute administration of imipramine alone can be effective on depressive-like symptoms but not on neurotrophic factor alterations present in BD.


Assuntos
Transtorno Bipolar , Animais , Ratos , Antimaníacos/farmacologia , Antimaníacos/uso terapêutico , Transtorno Bipolar/induzido quimicamente , Fator Neurotrófico Derivado do Encéfalo/uso terapêutico , Modelos Animais de Doenças , Imipramina/farmacologia , Imipramina/uso terapêutico , Lítio/farmacologia , Lítio/uso terapêutico , Mania , Fatores de Crescimento Neural , Ouabaína/farmacologia , Ouabaína/uso terapêutico , Ratos Wistar , Ácido Valproico
8.
Sci Rep ; 12(1): 12598, 2022 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-35871157

RESUMO

Zika virus (ZIKV) is an emerging arbovirus associated with neurological disorders. Currently, no specific vaccines or antivirals are available to treat the ZIKV infection. Ouabain, a cardiotonic steroid known as Na+/K+-ATPase inhibitor, has been previously described as an immunomodulatory substance by our group. Here, we evaluated for the first time the antiviral activity of this promising substance against a Brazilian ZIKV strain. Vero cells were treated with different concentrations of ouabain before and after the infection with ZIKV. The antiviral effect was evaluated by the TCID50 method and RT-qPCR. Ouabain presented a dose-dependent inhibitory effect against ZIKV, mainly when added post infection. The reduction of infectious virus was accompanied by a decrease in ZIKV RNA levels, suggesting that the mechanism of ZIKV inhibition by ouabain occurred at the replication step. In addition, our in silico data demonstrated a conformational stability and favorable binding free energy of ouabain in the biding sites of the NS5-RdRp and NS3-helicase proteins, which could be related to its mechanism of action. Taken together, these data demonstrate the antiviral activity of ouabain against a Brazilian ZIKV strain and evidence the potential of cardiotonic steroids as promising antiviral agents.


Assuntos
Glicosídeos Cardíacos , Infecção por Zika virus , Zika virus , Animais , Antivirais/uso terapêutico , Brasil , Glicosídeos Cardíacos/farmacologia , Chlorocebus aethiops , Ouabaína/farmacologia , Células Vero , Replicação Viral , Zika virus/fisiologia
9.
Braz J Med Biol Res ; 55: e11938, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35857994

RESUMO

The aim of this study was to assess the effect of two types of stressors, regarding the extent of involvement of ouabain (OUA), hippocampal sodium/potassium ATPase (NKA) expression, and the hippocampal corticosterone receptors (CR)/melatonin receptors (MR) expression ratio, on the behavioral and cardiovascular responses and on the hippocampal cornu ammonis zone 3 (CA3) and dentate gyrus (DG). Thirty adult male Wistar albino rats aged 7-8 months were exposed to either chronic immobilization or a disturbed dark/light cycle and treated with either ouabain or vehicle. In the immobilized group, in the absence of hippocampal corticosterone (CORT) changes, rats were non-responsive to stress, despite experiencing increased pulse rate, downregulated hippocampal sodium/potassium pump, and enhanced hippocampal CR/MR expression ratio. Prolonged darkness precipitated a reduced upright attack posture, with elevated CORT against hippocampal MR downregulation. Both immobilization and, to a lesser extent, prolonged darkness stress resulted in histopathological and ultrastructural neurodegenerative changes in the hippocampus. OUA administration did not change the behavioral resilience in restrained rats, despite persistence of the underlying biochemical derangements, added to decreased CORT. On the contrary, with exposure to short photoperiods, OUA reverted the behavior towards a combative reduction of inactivity, with unvaried CR/MR and CORT, while ameliorating hippocampal neuro-regeneration, with co-existing NKA and MR repressions. Therefore, the extent of OUA, hippocampal NKA expression, and CR/MR expression, and subsequent behavioral and cardiac responses and hippocampal histopathology, differ according to the type of stressor, whether immobilization or prolonged darkness.


Assuntos
Melatonina , Ouabaína , Animais , Corticosterona , Hipocampo/metabolismo , Masculino , Melatonina/metabolismo , Melatonina/farmacologia , Ouabaína/metabolismo , Ouabaína/farmacologia , Ratos , Ratos Wistar , Receptores de Melatonina/metabolismo , Receptores de Esteroides , Sódio , ATPase Trocadora de Sódio-Potássio/metabolismo , ATPase Trocadora de Sódio-Potássio/farmacologia
10.
Int Immunopharmacol ; 109: 108808, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35504206

RESUMO

OBJECTIVE: Ouabain, an inhibitor of Na+/K+-ATPase, is a type of endogenous hormone synthesized in the adrenal cortex and hypothalamus. Previous studies found that ouabain potently inhibited acute inflammatory reactions such as type 2 inflammation and regulated immunological processes. In this study, we aimed to investigate ouabain effect on allergic asthma. METHODS: BALB/c mice were submitted to chronic airway allergic inflammation induced by an ovalbumin (OVA) protocol. The animals were treated with ouabain or standard drug, budesonide. The following parameters were evaluated: cell migration, cytokine profile, IgE levels, lung histological modifications and MAPK activation. RESULTS: At first, it was observed that ouabain reduced OVA-induced cell migration into the lung, observed by bronchoalveolar lavage fluid (BALF) cell counting and lung histological analysis (HE stain). Additionally, ouabain negatively modulated alarmins (IL-33 and TSLP), Th2 high cytokines levels (IL-1ß and IL-4) and tissue remodeling markers such as TNF-α and TGF-ß. Treatment with ouabain also reduced OVA-specific IgE titers in BALF and serum, respectively, when compared to the OVA group. Lung histological parameters, including collagen deposition and mucus production induced by OVA were also attenuated by ouabain treatment. Finally, our results showed that p38 mitogen-activated protein kinase (MAPK) signaling pathways were suppressed by ouabain in this model. All these parameters were reduced by budesonide, a steroidal anti-inflammatory standard drug. CONCLUSION: These data together suggest that, in addition to its acute anti-inflammatory action, ouabain is also able to modulate allergic asthma.


Assuntos
Remodelação das Vias Aéreas , Asma , Ouabaína , Animais , Anti-Inflamatórios/farmacologia , Asma/induzido quimicamente , Asma/tratamento farmacológico , Líquido da Lavagem Broncoalveolar , Budesonida/farmacologia , Citocinas/metabolismo , Modelos Animais de Doenças , Imunoglobulina E , Inflamação/tratamento farmacológico , Pulmão/patologia , Camundongos , Camundongos Endogâmicos BALB C , Ouabaína/farmacologia , Ovalbumina
11.
Neurochem Res ; 47(3): 723-738, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34783975

RESUMO

Ouabain is a classic Na+K+ATPase ligand and it has been described to have neuroprotective effects on neurons and glial cells at nanomolar concentrations. In the present work, the neuroprotective and immunomodulatory potential of ouabain was evaluated in neonatal rat retinal cells using an optic nerve axotomy model in vitro. After axotomy, cultured retinal cells were treated with ouabain (3 nM) at different periods. The levels of important inflammatory receptors in the retina such as TNFR1/2, TLR4, and CD14 were analyzed. We observed that TNFR1, TLR4, and CD14 were decreased in all tested periods (15 min, 45 min, 24 h, and 48 h). On the other hand, TNFR2 was increased after 24 h, suggesting an anti-inflammatory potential for ouabain. Moreover, we showed that ouabain also decreased Iba-1 (microglial marker) density. Subsequently, analyses of retrograde labeling of retinal ganglion cells (RGC) were performed after 48 h and showed that ouabain-induced RGC survival depends on autophagy. Using an autophagy inhibitor (3-methyladenine), we observed a complete blockage of the ouabain effect. Western blot analyses showed that ouabain increases the levels of autophagy proteins (LC3 and Beclin-1) coupled to p-CREB transcription factor and leads to autophagosome formation. Additionally, we found that the ratio of cleaved/pro-caspase-3 did not change after ouabain treatment; however, p-JNK density was enhanced. Also, ouabain decreased reactive oxygen species production immediately after axotomy. Taken together, our results suggest that ouabain controls neuroinflammation in the retina following optic nerve axotomy and promotes RGC neuroprotection through activation of the autophagy pathway.


Assuntos
Adenosina Trifosfatases , Ouabaína , Adenosina Trifosfatases/metabolismo , Adenosina Trifosfatases/farmacologia , Animais , Autofagia/fisiologia , Axotomia , Sobrevivência Celular , Doenças Neuroinflamatórias , Nervo Óptico/fisiologia , Ouabaína/metabolismo , Ouabaína/farmacologia , Ratos , Espécies Reativas de Oxigênio/metabolismo , Retina/metabolismo
12.
Cardiovasc Toxicol ; 22(1): 78-87, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34655414

RESUMO

In the present study, we investigated the cardioactive glycosides oleandrin and ouabain, and compared them to digoxin in a model of cardiotoxicity induced by doxorubicin. Adult rats were distributed into four experimental groups. Each group was challenged with a single intraperitoneal application of doxorubicin at a dose of 12 mg/kg. Then, they were treated with saline solution and the glycosides oleandrin, ouabain, and digoxin at a dose of 50 µg/kg, for 7 days. They underwent echocardiography, electrocardiography, hematologic, biochemical tests, and microscopic evaluation of the heart. All animals presented congestive heart failure, which was verified by a reduction in the ejection fraction. Oleandrin and digoxin were able to significantly reduce (p < 0.05) the eccentric remodeling caused by doxorubicin. Oleandrin and digoxin were significantly lower (p < 0.05) than the control group in maintaining systolic volume and left ventricular volume in diastole. Other parameters evaluated did not show significant statistical differences. All animals showed an increase in erythrocyte count, and an increase in the duration of the QRS complex on the ECG and myocardial necrosis at the histopathological analysis. It is concluded that the glycosides oleandrin, ouabain, and digoxin in the used dosage do not present therapeutic potential for the treatment of congestive heart failure caused by doxorubicin.


Assuntos
Cardenolídeos/farmacologia , Glicosídeos Cardíacos/farmacologia , Cardiotônicos/farmacologia , Digoxina/farmacologia , Insuficiência Cardíaca/tratamento farmacológico , Ouabaína/farmacologia , Volume Sistólico/efeitos dos fármacos , Função Ventricular Esquerda/efeitos dos fármacos , Remodelação Ventricular/efeitos dos fármacos , Animais , Cardenolídeos/toxicidade , Glicosídeos Cardíacos/toxicidade , Cardiotônicos/toxicidade , Cardiotoxicidade , Digoxina/toxicidade , Modelos Animais de Doenças , Doxorrubicina , Insuficiência Cardíaca/induzido quimicamente , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/fisiopatologia , Ouabaína/toxicidade , Ratos Wistar , Recuperação de Função Fisiológica
13.
Br J Pharmacol ; 179(8): 1512-1524, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-33644859

RESUMO

Na+ /K+ -ATPase, a transmembrane protein essential for maintaining the electrochemical gradient across the plasma membrane, acts as a receptor for cardiotonic steroids such as ouabain. Cardiotonic steroids binding to Na+ /K+ -ATPase triggers signalling pathways or inhibits Na+ /K+ -ATPas activity in a concentration-dependent manner, resulting in a modulation of Ca2+ levels, which are essential for homeostasis in neurons. However, most of the pharmacological strategies for avoiding neuronal death do not target Na+ /K+ -ATPase activity due to its complexity and the poor understanding of the mechanisms involved in Na+ /K+ -ATPase modulation. The present review aims to discuss two points regarding the interplay between Na+ /K+ -ATPase and Ca2+ signalling in the brain. One, Na+ /K+ -ATPase impairment causing illness and neuronal death due to Ca2+ signalling and two, benefits to the brain by modulating Na+ /K+ -ATPase activity. These interactions play an essential role in neuronal cell fate determination and are relevant to find new targets for the treatment of neurodegenerative diseases. LINKED ARTICLES: This article is part of a themed issue on Building Bridges in Neuropharmacology. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.8/issuetoc.


Assuntos
Glicosídeos Cardíacos , Ouabaína , Cálcio/metabolismo , Sinalização do Cálcio , Glicosídeos Cardíacos/metabolismo , Glicosídeos Cardíacos/farmacologia , Íons/metabolismo , Neurônios/metabolismo , Ouabaína/metabolismo , Ouabaína/farmacologia , Sódio/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo
14.
Acta cir. bras ; 37(11): e371102, 2022. tab, graf, ilus
Artigo em Inglês | VETINDEX | ID: biblio-1415447

RESUMO

Purpose: To investigate the role of renal denervation (RDN) on endogenous ouabain (EO) secretion in spontaneously hypertensive rats (SHR). Methods: Sixteen 12-week-old male SHR were randomly separated into the renal denervation group (RDNX group) and sham operation group (sham group), and eight age-matched Wistar Kyoto rats (WKY) were served as control group. EO concentrations, the Na+- K+-ATPaseactivity, and the expression of Na+-K+-ATPase were assessed. Results: EO levels in serum, kidneys and hypothalamus of sham group were higher than in RDNX group (p < 0.05). Renal Na+-K+-ATPase activity subjected to denervation surgery showed significantly reduction when compared with the sham groups (p < 0.05). A positive correlation existed between norepinephrine (NE) content and Na+-K+-ATPase activity in the kidney (r2 = 0.579). Renal Na+-K+-ATPase α1 subunit mRNA expression was down-regulated in the RDNX group compared with the sham group (P < 0.05), while renal Na+-K+-ATPase α1 subunit mRNA expression was no statistical significance between the groups (P = 0.63). Immunohistochemical analysis showed that there were significant differences in the renal expression of Na+-K+-ATPasebetween the three groups (P < 0.05). Conclusions: These experiments demonstrate that RDN exerted an anti-hypertensive effect with reduction of EO levels and Na+-K+-ATPase activity and Na+-K+-ATPase α1 subunit expression of kidney in SHR.


Assuntos
Animais , Ratos , Ouabaína , ATPase Trocadora de Sódio-Potássio , Denervação , Hipertensão , Animais de Laboratório
15.
Inflammopharmacology ; 29(6): 1829-1833, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34792671

RESUMO

Ouabain is a cardiac steroid hormone with immunomodulatory effects. It inhibits neutrophils migration induced by different stimuli, but little is known about the mechanisms involved in this effect. Thus, the aim of this study was to evaluate the ouabain effect on chemotactic signaling pathways in neutrophils. For that, mice neutrophils were isolated from bone marrow, treated with ouabain (1, 10, and 100 nM) for 2 h, submitted to transwell chemotaxis assay and flow cytometry analysis of Akt, ERK, JNK, and p38 phosphorylation induced by zymosan. Ouabain treatment (1, 10 and, 100 nM) reduces neutrophil chemotaxis induced by chemotactic peptide fMLP, but this substance did not inhibit Akt, ERK, and JNK activation induced by zymosan. However, ouabain (1 and 10 nM) reduced p38 phosphorylation in zymosan-stimulated neutrophils. These results suggest that ouabain may interfere in neutrophil migration through p38 MAPK inhibition.


Assuntos
Neutrófilos/efeitos dos fármacos , Ouabaína/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Animais , Movimento Celular/efeitos dos fármacos , Quimiotaxia de Leucócito/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Citometria de Fluxo , Camundongos , Neutrófilos/metabolismo , Ouabaína/administração & dosagem , Fosforilação/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
16.
J Membr Biol ; 254(5-6): 499-512, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34716469

RESUMO

We have previously shown that 21-benzylidene digoxin (21-BD) increases the total cholesterol and phospholipid content on the membrane of HeLa cells. Lipid modulation caused by cardiotonic steroids (CTS) is still unexplored. Therefore, the aim of the present study was to evaluate the cholesterol and phospholipid modulation of the cell membrane caused by ouabain and 21-BD and the possible involvement of the caveolae on this modulation. For this, one cell line containing caveolae (HeLa) and other not containing (Caco-2) were used. The modulation of the lipid profile was evaluated by total cholesterol and phospholipids measurements, and identification of membrane phospholipids by HPTLC. The cholesterol distribution was evaluated by filipin staining. The caveolin-1 expression was evaluated by Western Blotting. Ouabain had no effect on the total membrane lipid content in both cell lines. However, 21-BD increased total membrane phospholipid content and had no effect on the membrane cholesterol content in Caco-2 cells. CTS were not able to alter the specific phospholipids content. In the filipin experiments, 21-BD provoked a remarkable redistribution of cholesterol to the perinuclear region of HeLa cells. In Caco-2 cells, it was observed only a slight increase in cholesterol, especially as intracellular vesicles. The caveolin-1 expression was not altered by any of the compounds. Our data mainly show different effects of two cardiotonic steroids. Ouabain had no effect on the lipid profile of cells, whereas 21-BD causes important changes in cholesterol and phospholipid content. Therefore, the modulation of cholesterol content in the plasma membrane of HeLa cells is not correlated with the expression of caveolin-1.


Assuntos
Glicosídeos Cardíacos/metabolismo , Células CACO-2 , Caveolina 1 , Colesterol , Filipina , Células HeLa , Humanos , Ouabaína/farmacologia , Fosfolipídeos
17.
Int J Mol Sci ; 22(12)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200582

RESUMO

Ouabain is a cardiac glycoside that has been described as a hormone, with interesting effects on epithelial physiology. We have shown previously that ouabain induces gap junctional intercellular communication (GJIC) in wild, sensitive cells (MDCK-S), but not in cells that have become insensitive (MDCK-I) by modifying their Na+-K+-ATPase. We have also demonstrated that prostaglandin E2 (PGE2) is able to induce increased GJIC by a mechanism other than ouabain, that does not depend on Na+-K+-ATPase. In this work we show, by dye transfer assays, that when MDCK-S and MDCK-I are randomly mixed, to form monolayers, the latter stablish GJIC, because of stimulation by a compound released to the extracellular media, by MDCK-S cells, after treatment with ouabain, as evidenced by the fact that monolayers of only MDCK-I cells, treated with a conditioned medium (CM) that is obtained after incubation of MDCK-S monolayers with ouabain, significantly increase their GJIC. The further finding that either (1) pre-treatment with COX-2 inhibitors or (2) addition to CM of antagonists of EP2 receptor abolish CM's ability to induce GJIC in MDCK-I monolayers indicate that PGE2 is the GJIC-inducing compound. Therefore, these results indicate that, in addition to direct stimulation, mediated by Na+-K+-ATPase, ouabain enhances GJIC indirectly through the paracrine production of PGE2.


Assuntos
Cardiotônicos/farmacologia , Dinoprostona/metabolismo , Junções Comunicantes/fisiologia , Ouabaína/farmacologia , Comunicação Parácrina , Animais , Cães , Células Madin Darby de Rim Canino , Transdução de Sinais
18.
Vascul Pharmacol ; 139: 106880, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34052431

RESUMO

AIM: Previous studies raise cyclooxygenase (COX) activation as a possible mechanism involved in the pathophysiology of ouabain-induced hypertension. We hypothesized that inhibition of COX-2 activity might prevent ouabain-induced vascular dysfunction and worsening of hypertension in spontaneously hypertensive rats (SHR). METHODS: SHR were exposed to ouabain or vehicle and treated or not with the selective COX-2 inhibitor nimesulide for 5 weeks. Systolic blood pressure was measured by plethysmography. Vascular reactivity by wire myograph and protein expression by Western-blot were assessed in mesenteric resistance arteries (MRA) of groups. Thromboxane A2 (TXA2) production by ELISA was evaluated in MRA supernatants of groups. RESULTS: Noradrenaline-induced maximal contraction (Emax) was greater in MRA from SHR receiving ouabain than those of vehicle group. In situ inhibition of COX-2, TXA2 synthase, or TP receptor reduced the Emax to noradrenaline in MRA of ouabain to vehicle levels. TXA2 production was higher in ouabain than in vehicle group. Ouabain enhanced expression of cytoplasmic tyrosine kinase Src (c-Src)/ERK1/2/COX-2/TXA2 synthase/TP receptor in SHR MRA, but did not change NFkB/iKB ratio. Anticontractile effect of nitric oxide (NO) was smaller in MRA from ouabain- than vehicle-treated SHR, as well as eNOS and nNOS expression. Nimesulide co-treatment prevented the ouabain-induced worsening of hypertension and noradrenaline MRA hypercontractility in SHR. CONCLUSION: Ouabain worsen hypertension and induce MRA hypercontractility in SHR associated with upregulated c-Src/ERK1/2/COX-2/TXA2 synthase/TXA2/TP receptor axis. These effects were prevented by COX-2 inhibition.


Assuntos
Hipertensão , Ouabaína , Animais , Pressão Sanguínea , Ciclo-Oxigenase 2/metabolismo , Endotélio Vascular , Hipertensão/induzido quimicamente , Hipertensão/tratamento farmacológico , Hipertensão/prevenção & controle , Artérias Mesentéricas/metabolismo , Ouabaína/farmacologia , Ratos , Ratos Endogâmicos SHR , Vasoconstrição , Vasodilatação
19.
Environ Toxicol ; 36(7): 1338-1348, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33760381

RESUMO

Ouabain is a steroid described as a compound extracted from plants that is capable of binding to Na+ , K+ -ATPase, inhibiting ion transport and triggering cell signaling pathways. Due to its positive ionotropic effect, ouabain was used for more than 200 years for the treatment of cardiac dysfunctions. Numerous antitumor effects of ouabain have been described so far; however, its role on thyroid cancer is still poorly understood. Therefore, the aim of the present work was to evaluate the effect of ouabain on the biology of human papillary thyroid cancer cells. For this, three human thyroid cell lines were used: NTHY-ori, a non-tumor lineage, BCPAP and TPC-1, both derived from papillary carcinomas. Cells were cultured in the presence or absence of ouabain. Subsequently, we evaluated its effects on the viability, cell death, cell cycle, and migratory ability of these cell lines. We also investigated the impact of ouabain in IL-6/IL-6R and epithelial to mesenchymal transition markers expression. Our results indicate that ouabain (10-7 M), decreased the number of NTHY-ori, TPC-1 and BCPAP viable cells and induced cell cycle arrest after in vitro culture, but did not appear to promote cell death. In TPC-1 cells ouabain also inhibited cell migration; increased IL-6/IL-6R expression and IL-6 secretion; and diminished vimentin and SNAIL-1 expression. Collectively, our results indicate that ouabain has an antitumoral role on human papillary thyroid carcinomas in vitro. Even though additional studies are necessary, our work contributes to the discussion of the possibility of new clinical trials of ouabain.


Assuntos
Carcinoma Papilar , Neoplasias da Glândula Tireoide , Carcinoma Papilar/tratamento farmacológico , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Transição Epitelial-Mesenquimal , Humanos , Ouabaína , Câncer Papilífero da Tireoide , Neoplasias da Glândula Tireoide/tratamento farmacológico
20.
Int Immunopharmacol ; 86: 106772, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32674049

RESUMO

Ouabain (OUA) is a glycoside shown to modulate B and T lymphocytes. Nevertheless, ouabain effects on B16F10 melanoma immune response, a mouse lineage that mimics human melanoma, are still unknown. Our aim was to study how OUA in vivo treatment modulates lymphocytes and if it improves the response against B16F10 cells. C57BL/6 mice were pre-treated with intraperitoneal (i.p) injection of OUA (0.56 mg/Kg) for three consecutive days. On the 4th day, 106 B16F10 cells or vehicle were i.p. injected. Animals were euthanized on days 4th and 21st for organs removal and subsequent lymphocyte analyses by flow cytometry. In vivo ouabain-treatment reduced regulatory T cells in the spleen in both melanoma and non-melanoma groups. Ouabain preserved the number and percentage of B lymphocytes in peripheral organs of melanoma-injected mice. Melanoma-injected mice pre-treated with OUA also survive longer. Our findings contribute to a better understanding of OUA immunological effects in a melanoma model.


Assuntos
Antineoplásicos/uso terapêutico , Linfócitos B/imunologia , Melanoma/tratamento farmacológico , Ouabaína/uso terapêutico , Neoplasias Cutâneas/tratamento farmacológico , Linfócitos T Reguladores/imunologia , Animais , Modelos Animais de Doenças , Feminino , Humanos , Imunomodulação , Injeções Intraperitoneais , Melanoma Experimental , Camundongos , Camundongos Endogâmicos C57BL
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