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1.
Arq. bras. cardiol ; 110(1): 44-51, Jan. 2018. graf
Article in English | LILACS | ID: biblio-887998

ABSTRACT

Resumo Background: Melatonin is a neuroendocrine hormone synthesized primarily by the pineal gland that is indicated to effectively prevent myocardial reperfusion injury. It is unclear whether melatonin protects cardiac function from reperfusion injury by modulating intracellular calcium homeostasis. Objective: Demonstrate that melatonin protect against myocardial reperfusion injury through modulating IP3R and SERCA2a to maintain calcium homeostasis via activation of ERK1 in cardiomyocytes. Methods: In vitro experiments were performed using H9C2 cells undergoing simulative hypoxia/reoxygenation (H/R) induction. Expression level of ERK1, IP3R and SERCA2a were assessed by Western Blots. Cardiomyocytes apoptosis was detected by TUNEL. Phalloidin-staining was used to assess alteration of actin filament organization of cardiomyocytes. Fura-2 /AM was used to measure intracellular Ca2+ concentration. Performing in vivo experiments, myocardial expression of IP3R and SERCA2a were detected by immunofluorescence staining using myocardial ischemia/ reperfusion (I/R) model in rats. Results: In vitro results showed that melatonin induces ERK1 activation in cardiomyocytes against H/R which was inhibited by PD98059 (ERK1 inhibitor). The results showed melatonin inhibit apoptosis of cardiomyocytes and improve actin filament organization in cardiomyocytes against H/R, because both could be reversed by PD98059. Melatonin was showed to reduce calcium overload, further to inhibit IP3R expression and promote SERCA2a expression via ERK1 pathway in cardiomyocytes against H/R. Melatonin induced lower IP3R and higher SERCA2a expression in myocardium that were reversed by PD98059. Conclusion: melatonin-induced cardioprotection against reperfusion injury is at least partly through modulation of IP3R and SERCA2a to maintain intracellular calcium homeostasis via activation of ERK1.


Resumo Fundamento: A melatonina é um hormônio neuroendócrino sintetizado principalmente pela glândula pineal que é indicado para prevenir efetivamente a lesão de reperfusão miocárdica. Não está claro se a melatonina protege a função cardíaca da lesão de reperfusão através da modulação da homeostase do cálcio intracelular. Objetivo: Demonstrar que a melatonina protege contra a lesão de reperfusão miocárdica através da modulação de IP3R e SERCA para manter a homeostase de cálcio por meio da ativação de ERK1 em cardiomiócitos. Métodos: Foram realizados experimentos in vitro usando células H9C2 submetidas a indução de hipoxia / reoxigenação simulada (H/R). O nível de expressão de ERK1, IP3R e SERCA foi avaliado por Western Blots. A apoptose de cardiomiócitos foi detectada por TUNEL. A coloração de faloidina foi utilizada para avaliar a alteração da organização de filamentos de actina dos cardiomiócitos. Fura-2 / AM foi utilizado para medir a concentração intracelular de Ca2+. Realizando experiências in vivo, a expressão miocárdica de IP3R e SERCA foi detectada por coloração com imunofluorescência usando modelo de isquemia miocárdica / reperfusão (I/R) em ratos. Resultados: resultados in vitro mostraram que a melatonina induz a ativação de ERK1 em cardiomiócitos contra H/R que foi inibida por PD98059 (inibidor de ERK1). Os resultados mostraram que a melatonina inibe a apoptose dos cardiomiócitos e melhora a organização do filamento de actina em cardiomiócitos contra H/R, pois ambas poderiam ser revertidas pela PD98059. A melatonina mostrou reduzir a sobrecarga de cálcio, além de inibir a expressão de IP3R e promover a expressão de SERCA através da via ERK1 em cardiomiócitos contra H/R. A melatonina induziu menor IP3R e maior expressão de SERCA no miocárdio que foram revertidas pela PD98059. Conclusão: a cardioproteção induzida pela melatonina contra lesão de reperfusão é pelo menos parcialmente através da modulação de IP3R e SERCA para manter a homeostase de cálcio intracelular via ativação de ERK1.


Subject(s)
Animals , Male , Rats , Myocardial Reperfusion Injury/metabolism , Myocardial Reperfusion Injury/prevention & control , MAP Kinase Signaling System/drug effects , Myocytes, Cardiac/drug effects , Sarcoplasmic Reticulum Calcium-Transporting ATPases/drug effects , Inositol 1,4,5-Trisphosphate Receptors/drug effects , Melatonin/pharmacology , Myocardial Reperfusion Injury/pathology , Rats, Sprague-Dawley , Myocytes, Cardiac/pathology , Disease Models, Animal , Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism , Inositol 1,4,5-Trisphosphate Receptors/metabolism
2.
Biol. Res ; 48: 1-5, 2015. graf
Article in English | LILACS | ID: biblio-950819

ABSTRACT

BACKGROUND: In the central nervous system, interleukin-10 (IL-10) provides trophic and survival effects directly on neurons, modulates neurite plasticity, and has a pivotal importance in the neuronal regeneration in neurodegenerative and neuroinflammatory conditions. This cytokine is primarily produced by glial cells and has beneficial effects on the neuronal viability. However, the mechanisms of IL-10-elicited neuroprotection are not clear. RESULTS: Membrane preparations, isolated from wild-type (Wt) and IL-10 knockout (KO) mice brain were used in this study. It has been shown that compared to wild-type mice, in IL-10 KO mice brain, the amount of immunoglobulin binding protein (BiP) is greatly increased, whereas the content of sigma receptor-1 (SigR1) is not changed significantly. Co-immunoprecipitation experiments have shown that the association of SigR1 with small GTPase Rac1 (Ras-related C3 botulinum toxin substrate 1), NR2B subunit of NMDA-receptor (NMDAR) and inositol-3-phosphate receptor (IP3R) is higher in the IL-10 KO mice brain than in the Wt mice brain. Besides, we have found that either glutamate or sigma ligands, separately or together, do not change glutamate-induced NADPH-oxidase (NOX) activity in Wt-type mice brain membrane preparations, whereas in IL-10 KO mice high concentration of glutamate markedly increases the NOX-dependent production of reactive oxygen species (ROS). Glutamate-dependent ROS production was decreased to the normal levels by the action of sigma-agonists. CONCLUSIONS: It has been concluded that IL-10 deprivation, at least in part, can lead to the induction of ER-stress, which causes BiP expression and SigR1 redistribution between components of endoplasmic reticulum (ER) and plasma membrane. Moreover, IL-10 deficiency can change the specific organization of NMDAR, increasing the surface expression of SigR1-sensitive NR2B-containing NMDAR. In these conditions, glutamate-dependent ROS production is greatly increased leading to the initiation of apoptosis. In this circumstances, sigma-ligands could play a preventive role against NMDA receptor-mediated excitotoxicity.


Subject(s)
Animals , Male , Mice , Brain/metabolism , Interleukin-10/genetics , Receptors, sigma/metabolism , Glutamic Acid/metabolism , NADPH Oxidases/metabolism , Cell Membrane/metabolism , Receptors, sigma/classification , Receptors, sigma/agonists , Reactive Oxygen Species/analysis , Reactive Oxygen Species/metabolism , Receptors, N-Methyl-D-Aspartate/classification , Receptors, N-Methyl-D-Aspartate/metabolism , rac1 GTP-Binding Protein/metabolism , Immunoprecipitation , Endoplasmic Reticulum/metabolism , Inositol 1,4,5-Trisphosphate Receptors/metabolism , Gene Knockdown Techniques , Heat-Shock Proteins/metabolism , Mice, Inbred C57BL , Neurons/metabolism
3.
Yonsei Medical Journal ; : 311-321, 2008.
Article in English | WPRIM | ID: wpr-30669

ABSTRACT

PURPOSE: The sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA), encoded by ATP2A2, is an essential component for G-protein coupled receptor (GPCR)-dependent Ca(2+) signaling. However, whether the changes in Ca(2+) signaling and Ca(2+) signaling proteins in parotid acinar cells are affected by a partial loss of SERCA2 are not known. MATERIALS AND METHODS: In SERCA2(+/-) mouse parotid gland acinar cells, Ca(2+) signaling, expression levels of Ca(2+) signaling proteins, and amylase secretion were investigated. RESULTS: SERCA2(+/-) mice showed decreased SERCA2 expression and an upregulation of the plasma membrane Ca(2+) ATPase. A partial loss of SERCA2 changed the expression level of 1, 4, 5-tris-inositolphosphate receptors (IP(3)Rs), but the localization and activities of IP3Rs were not altered. In SERCA2(+/-) mice, muscarinic stimulation resulted in greater amylase release, and the expression of synaptotagmin was increased compared to wild type mice. CONCLUSION: These results suggest that a partial loss of SERCA2 affects the expression and activity of Ca(2+) signaling proteins in the parotid gland acini, however, overall Ca(2+) signaling is unchanged.


Subject(s)
Amylases/metabolism , Animals , Blotting, Western , Calcium/metabolism , Calcium Signaling/drug effects , Carbachol/pharmacology , Immunohistochemistry , Inositol 1,4,5-Trisphosphate Receptors/metabolism , Mice , Mice, Knockout , Parotid Gland/metabolism , Sarcoplasmic Reticulum Calcium-Transporting ATPases/genetics , Signal Transduction/drug effects
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