RESUMO
Knowledge of glycogen synthase kinase 3ß (GSK3ß) activity and the molecules identified that regulate its function in infections caused by pathogenic microorganisms is crucial to understanding how the intensity of the inflammatory response can be controlled in the course of infections. In recent years many reports have described small molecular weight synthetic and natural compounds, proteins, and interference RNA with the potential to regulate the GSK3ß activity and reduce the deleterious effects of the inflammatory response. Our goal in this review is to summarize the most recent advances on the role of GSK3ß in the inflammatory response caused by bacteria, bacterial virulence factors (i.e. LPS and others), viruses, and parasites and how the regulation of its activity, mainly its inhibition by different type of molecules, modulates the inflammation.
Assuntos
Infecções Bacterianas/imunologia , Glicogênio Sintase Quinase 3 beta/fisiologia , Inflamação/etiologia , Doenças Parasitárias/imunologia , Viroses/imunologia , Animais , Glicogênio Sintase Quinase 3 beta/antagonistas & inibidores , Humanos , FosforilaçãoRESUMO
Increased O-Linked ß-N-acetylglucosamine (O-GlcNAc) is observed in several pathologies, and unbalanced O-GlcNAcylation levels favor endothelial dysfunction. Whether augmented O-GlcNAc impacts the uterine artery (UA) function and how it affects the UA during pregnancy remains to be elucidated. We hypothesized that glucosamine treatment increases O-GlcNAc, leading to uterine artery dysfunction and this effect is prevented by pregnancy. Pregnant (P) and non-pregnant (NP) Wistar rats were treated with glucosamine (300 mg/kg; i.p.) for 21 days. Concentration response-curves (CRC) to acetylcholine (in the presence or absence of L-NAME) and sodium nitroprusside were performed in UAs. In NP rats, glucosamine treatment increased O-GlcNAc expression in UAs accompanied by decreased endothelium-dependent relaxation, which was abolished by L-NAME. Endothelial nitric oxide synthase (eNOS) activity and total Akt expression were decreased by glucosamine-treatment in NP rats. Further, NP rats treated with glucosamine displayed increased glycogen synthase kinase 3 beta (GSK3ß) activation and O-GlcNAc-transferase (OGT) expression in the UA. P rats treated with glucosamine displayed decreased O-GlcNAc in UAs and it was accompanied by improved relaxation to acetylcholine, whereas eNOS and GSK3ß activity and total Akt and OGT expression were unchanged. Sodium nitroprusside-induced relaxation was not changed in all groups, indicating that glucosamine treatment led to endothelial dysfunction in NP rats. The underlying mechanism is, at least in part, dependent on Akt/GSK3ß/OGT modulation. We speculate that during pregnancy, hormonal alterations play a protective role in preventing O-GlcNAcylation-induced endothelial dysfunction in the UAs.
Assuntos
Endotélio Vascular/efeitos dos fármacos , Glucosamina/farmacologia , Glicogênio Sintase Quinase 3 beta/fisiologia , Artéria Uterina/efeitos dos fármacos , Animais , Endotélio Vascular/fisiologia , Feminino , N-Acetilglucosaminiltransferases/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Gravidez , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos Wistar , Artéria Uterina/fisiologia , Vasodilatação/efeitos dos fármacosRESUMO
Patients with hyperthyroidism exhibit increased risk of development and progression of cardiac diseases. The activation of the renin-angiotensin system (RAS) has been indirectly implicated in these cardiac effects observed in hyperthyroidism. Angiotensin-(1-7) (Ang-(1-7)) has previously been shown to counterbalance pathological effects of angiotensin II (Ang II). The aim of the present study was to investigate the effects of elevated circulating Ang-(1-7) levels on cardiac effects promoted by hyperthyroidism in a transgenic rat (TG) model that constitutively overexpresses an Ang-(1-7)-producing fusion protein [TGR(A1-7)3292]. TG and wild-type (WT) rats received daily injections (i.p.) of triiodothyronine (T3; 7 µg/100 g of body weight (BW)) or vehicle for 14 days. In contrast with WT rats, the TG rats did not develop cardiac hypertrophy after T3 treatment. Indeed, TG rats displayed reduced systolic blood pressure (SBP) and cardiac hyperdynamic condition induced by hyperthyroidism. Moreover, increased plasma levels of Ang II observed in hyperthyroid WT rats were prevented in TG rats. TG rats were protected from glycogen synthase kinase 3ß (GSK3ß) inactivation and nuclear factor of activated T cells (NFAT) nuclear accumulation induced by T3. In vitro studies evidenced that Ang-(1-7) prevented cardiomyocyte hypertrophy and GSK3ß inactivation induced by T3. Taken together, these data reveal an important cardioprotective action of Ang-(1-7) in experimental model of hyperthyroidism.
Assuntos
Angiotensina I/fisiologia , Cardiomegalia/etiologia , Glicogênio Sintase Quinase 3 beta/fisiologia , Hipertireoidismo/complicações , Fatores de Transcrição NFATC/fisiologia , Fragmentos de Peptídeos/fisiologia , Angiotensina I/sangue , Angiotensina I/farmacologia , Animais , Cardiomegalia/sangue , Cardiomegalia/diagnóstico por imagem , Células Cultivadas , Ecocardiografia , Hipertireoidismo/sangue , Hipertireoidismo/induzido quimicamente , Masculino , Miócitos Cardíacos/citologia , Miócitos Cardíacos/efeitos dos fármacos , Fragmentos de Peptídeos/sangue , Fragmentos de Peptídeos/farmacologia , Ratos Sprague-Dawley , Ratos Transgênicos , Ratos Wistar , Sistema Renina-Angiotensina/fisiologia , Transdução de Sinais/fisiologia , Tri-Iodotironina/farmacologiaRESUMO
Testosterone induces cardiac hypertrophy through a mechanism that involves a concerted crosstalk between cytosolic and nuclear signaling pathways. Nuclear factor of activated T-cells (NFAT) is associated with the promotion of cardiac hypertrophy, glycogen synthase kinase-3ß (GSK-3ß) is considered to function as a negative regulator, mainly by modulating NFAT activity. However, the role played by calcineurin-NFAT and GSK-3ß signaling in testosterone-induced cardiac hypertrophy has remained unknown. Here, we determined that testosterone stimulates cardiac myocyte hypertrophy through NFAT activation and GSK-3ß inhibition. Testosterone increased the activity of NFAT-luciferase (NFAT-Luc) in a time- and dose-dependent manner, with the activity peaking after 24 h of stimulation with 100 nM testosterone. NFAT-Luc activity induced by testosterone was blocked by the calcineurin inhibitors FK506 and cyclosporine A and by 11R-VIVIT, a specific peptide inhibitor of NFAT. Conversely, testosterone inhibited GSK-3ß activity as determined by increased GSK-3ß phosphorylation at Ser9 and ß-catenin protein accumulation, and also by reduction in ß-catenin phosphorylation at residues Ser33, Ser37, and Thr41. GSK-3ß inhibition with 1-azakenpaullone or a GSK-3ß-targeting siRNA increased NFAT-Luc activity, whereas overexpression of a constitutively active GSK-3ß mutant (GSK-3ßS9A) inhibited NFAT-Luc activation mediated by testosterone. Testosterone-induced cardiac myocyte hypertrophy was established by increased cardiac myocyte size and [3H]-leucine incorporation (as a measurement of cellular protein synthesis). Calcineurin-NFAT inhibition abolished and GSK-3ß inhibition promoted the hypertrophy stimulated by testosterone. GSK-3ß activation by GSK-3ßS9A blocked the increase of hypertrophic markers induced by testosterone. Moreover, inhibition of intracellular androgen receptor prevented testosterone-induced NFAT-Luc activation. Collectively, these results suggest that cardiac myocyte hypertrophy induced by testosterone involves a cooperative mechanism that links androgen signaling with the recruitment of NFAT through calcineurin activation and GSK-3ß inhibition.