RESUMO
The aim of the present study was to investigate the mechanisms of CCAAT/enhancer-binding protein ß (C/EBPß) in cardiac myofibroblast (CMF) differentiation and in a rat model of cardiac fibrosis induced by experimental autoimmune myocarditis (EAM).In vitro studies performed in primary neonatal rat CMF revealed that silencing of C/EBPß expression (via lentiviral mediated shRNA strategies) was sufficient to reduce C/EBPß mRNA and protein levels as well as to decrease the expressions of actin cytoskeletal proteins, cofilin, and filamin A (FLNA). TGFß increased IL-1ß, IL-6 and TNF-a production in cardiac fibroblasts (CF), while C/EBPß knockdown reduced the secretion of these inflammatory mediators. In vivo studies performed in rats exhibiting EAM revealed that lentiviral-mediated silencing of C/EBPß was sufficient to reduce the expression of C/EBPß as well as inflammation and fibrosis in the hearts of EAM rats, when compared to controls. Echocardiography further revealed that C/EBPß knockdown was sufficient to significantly improve cardiac dimensions and function in EAM rats. Immunohistochemical results showed that C/EBPß knockdown attenuated the expression of C/EBPß protein as well as the expressions of collagen I, collagen III, MMP-2, MMP-9, and α-SMA in heart tissue sections from rats in the EAM + Lenti-shC/EBPß group.Strategies targeted at inhibiting C/EBPß expression can be potentially exploited to regulate cofilin and FLNA expression, thereby regulating actin polymerization/depolymerization, cytoskeleton rearrangement, and CF differentiation into CMF and the production of inflammatory cytokines. C/EBPß knock down reduces the degree of inflammation-mediated myocardial fibrosis in a rat model of EAM.
Assuntos
Doenças Autoimunes/metabolismo , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Diferenciação Celular/fisiologia , Miocardite/metabolismo , Miocárdio/patologia , Miofibroblastos/fisiologia , Animais , Doenças Autoimunes/imunologia , Doenças Autoimunes/patologia , Biomarcadores/metabolismo , Fibrose , Masculino , Miocardite/imunologia , Miocardite/patologia , Miocárdio/metabolismo , Miofibroblastos/patologia , Distribuição Aleatória , Ratos , Ratos Endogâmicos Lew , Ratos Sprague-DawleyRESUMO
AIMS: Research related to type 2 diabetes mellitus (DM) and parameters of electrocardiography (ECG) was limited. Patients with and without DM (NDM) were randomly enrolled in a study to exploit the influence of DM on planar QRS and T vectors derived from the Virtual Holter process. METHODS: A total of 216 (NDM) and 127 DM patients were consecutively and randomly recruited. We selected a 1-minute length of ECG, which was scheduled for analysis at 4 AM. After a series of calculating algorisms, we received the virtual planar vector parameters. RESULTS: Patients with DM were elderly (65.61 ± 12.08 vs 59.41 ± 16.86 years, P < 0.001); higher morbidity of hypertension (76.38% vs 58.14%, P < 0.001) and coronary artery disease (44.09% vs 32.41%, P = 0.03); thicker interventricular septum (10.92 ± 1.77 vs 10.08 ± 1.96 mm, P < 0.001) and left ventricular posterior wall (9.84 ± 1.38 vs 9.39 ± 1.66 mm, P = 0.03); higher lipid levels and average heart rate (66.67 ± 12.04 vs 61.87 ± 13.36 bpm, P < 0.01); higher angle of horizontal QRS vector (HQRSA, -2.87 ± 48.48 vs -19.00 ± 40.18 degrees, P < 0.01); lower maximal magnitude of horizontal T vector (HTV, 2.33 ± 1.47 vs 2.88 ± 1.89 mm, P = 0.01) and maximal magnitude of right side T vector (2.77 ± 1.55 vs 3.27 ± 1.92 mm, P = 0.03), and no difference in angle of frontal QRS-T vector (FQRSTA, 32.77 ± 54.20 vs 28.39 ± 52.87 degrees, P = 0.74) compared with patients having NDM. After adjusting for confounding factors, DM was significantly effective on FQRSTA (regression coefficient -40.0, 95%CI -66.4 to -13.6, P < 0.01), HQRSA (regression coefficient 22.6, 95%CI 2.5 to 42.8, P = 0.03), and HTV (regression coefficient 0.9, 95%CI 0.2 to 1.7, P = 0.01). Confounding factors included: sex, 2-hour postprandial blood glucose, smoking, triglyceride, apolipoprotein A, creatinine, left ventricular ejection fraction, and average heart rate. CONCLUSIONS: The risk factors of DM and lipid metabolism abnormality particularly apolipoprotein A significantly modified parameters of virtual planar QRS and T vector, including frontal QRS-T angle.
Assuntos
Diabetes Mellitus Tipo 2/complicações , Cardiomiopatias Diabéticas/diagnóstico , Eletrocardiografia Ambulatorial , Idoso , Apoproteína(a)/sangue , Diabetes Mellitus Tipo 2/fisiopatologia , Cardiomiopatias Diabéticas/fisiopatologia , Feminino , Humanos , Metabolismo dos Lipídeos , Masculino , Pessoa de Meia-Idade , Distribuição Aleatória , Fatores de RiscoRESUMO
Γ-aminobutyric acid (GABA) is a multifunctional molecule found in the nervous system and non-neuronal tissues. GABA receptors combine with GABA molecules and transmit signal stimuli into cells. In addition to traditional neurotransmission and regulation of secretion, GABA and GABA receptors are involved in cell differentiation and proliferation throughout peripheral organs, as well as in tumorigenesis. The exact mechanism of the GABAergic system in regulating tumor development is unclear, but many studies have revealed that GABA receptors exert critical regulative effects on tumor cell proliferation and migration. In this review, the molecular structure, distribution and biological function of GABA receptors associated with tumorigenesis are described. Recent advances in the elucidation of mechanisms underlying GABAergic signaling control over tumor growth are also discussed.