RESUMEN
The difference in the atrial organizational structure between patients with atrial fibrillation (AF) and those with sinus rhythm was investigated. In order to analyze the rationality in explaining the electrocardiogram (ECG) characteristics of AF with statistics data or tissue remodeling model, and the logical relationship between the hypothesis of pulmonary veins (PV) muscle sleeves and that of multi wavelets in mechanism of AF, we examined the expression of collagen volume fraction of type I (CVF-I) with picrosirius red staining, connexin 40 (Cx40) by immunohistochemistry, and intercalated disc (ID) using transmission electron microscope in atrial tissue. The results showed that there was significant difference in the expression of CVF-I (t=3.827, P<0.01), Cx40 (t=4.21, P<0.01), and groups of the ID that keeping the electrical transmission and atrial electrical coupling synchronization (t=15.116, P<0.001), but no significant difference was found in total IDs (t=0.611, P=0.543) between patients with AF and those with sinus rhythm. The quantitative differences in the tissue remodeling could not explain the ECG characteristics of AF. The number of normal IDs and abnormal distribution are the structural basis to trigger and maintain atrial electrical remodeling, and induce and maintain AF. Such histological reconstruction supports the hypothesis of multi wavelets and can also explain ECG features.
Asunto(s)
Fibrilación Atrial/metabolismo , Remodelación Atrial/fisiología , Conexinas/genética , Atrios Cardíacos/fisiopatología , Adulto , Anciano , Fibrilación Atrial/diagnóstico por imagen , Fibrilación Atrial/fisiopatología , Remodelación Atrial/genética , Electrocardiografía , Femenino , Corazón/diagnóstico por imagen , Atrios Cardíacos/diagnóstico por imagen , Humanos , Masculino , Microscopía Electrónica de Transmisión , Persona de Mediana Edad , Miocardio/metabolismo , Miocardio/patología , Venas Pulmonares/metabolismo , Venas Pulmonares/patología , Adulto Joven , Proteína alfa-5 de Unión ComunicanteRESUMEN
Acute liver injury seriously endangers human health. Liraglutide, a glucagon-like peptide-1 (GLP-1) analogue, has antioxidative effects in addition to being widely used in the treatment of type 2 diabetes and was reported to ameliorate liver diseases. The aim of this study was to evaluate the hepatoprotective effects of liraglutide on carbon tetrachloride (CCl4)-induced acute liver injury in mice and to investigate the mechanisms involved in this protective effect. Male BALB/c mice were pre-treated with liraglutide (200⯵g/kg/day) by hypodermic injection for 3 days before a 0.1% (v/v) CCl4 (10â¯ml/kg, dissolved in olive oil) intraperitoneal injection, or post-treated with liraglutide once immediately after a CCl4 intraperitoneal injection. The experimental data showed that liraglutide treatment significantly decreased the serum ALT and AST levels and ameliorated the liver histopathological changes induced by CCl4. In addition, liraglutide pre-treatment dramatically increased the number of proliferating cell nuclear antigen (PCNA)-positive hepatocytes and significantly reduced hepatocyte apoptosis after CCl4 treatment. As a consequence, liraglutide pre-treatment significantly prevented CCl4-induced malondialdehyde (MDA) production and increased the activity of the antioxidant superoxide dismutase (SOD) enzyme. In addition, liraglutide pre-treatment significantly ameliorated mitochondrial respiratory functions and ultrastructural features. Furthermore, liraglutide pre-treatment enhances the activation of the NRF2/HO-1 signaling pathway. In summary, liraglutide protects against CCl4-induced acute liver injury by protecting mitochondrial functions and inhibiting oxidative stress, which may partly involve the activation of NRF2/HO-1 signaling pathway.
Asunto(s)
Tetracloruro de Carbono , Enfermedad Hepática Inducida por Sustancias y Drogas/prevención & control , Liraglutida/farmacología , Sustancias Protectoras/farmacología , Animales , Apoptosis/efectos de los fármacos , Respiración de la Célula/efectos de los fármacos , Hemo-Oxigenasa 1/metabolismo , Hepatocitos/efectos de los fármacos , Hepatocitos/patología , Hígado/efectos de los fármacos , Hígado/patología , Masculino , Malondialdehído/metabolismo , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos BALB C , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Estrés Oxidativo/efectos de los fármacos , Antígeno Nuclear de Célula en Proliferación/metabolismo , Transducción de Señal/efectos de los fármacos , Superóxido Dismutasa/metabolismoRESUMEN
BACKGROUND: Advances in immunosuppressive therapy have significantly improved short-term but not long-term survival of cardiac transplant recipients; this is largely due to severe cardiac allograft vasculopathy (CAV). Glucagon-like peptide-1 receptor (GLP-1R)-based therapy exerts physiological effects on the cardiovascular system in addition to its traditional role in controlling glucose. We have investigated the effects of liraglutide, a GLP-1R agonist, on the development of CAV in a murine heart transplant model. METHODS: Heterotopic murine cardiac transplantation was performed with a major histocompatibility complex class II-mismatched model. Recipient mice were subcutaneously administered vehicle (0.9% saline solution) or liraglutide (300 µg·kg every 12 hours) from the day of transplantation. Allografts were harvested at 2 or 8 weeks and histologically analyzed. Inflammatory infiltrates were measured by immunohistochemistry, and immunofluorescence and western blotting analyzes were used to evaluate GLP-1R expression and markers of endothelial-to-mesenchymal transition (EndMT) in cardiac allografts and human coronary artery endothelial cells challenged with transforming growth factor-beta 1. RESULTS: Glucagon-like peptide-1 receptor was predominantly localized to vascular endothelial cells and was upregulated in cardiac allografts after liraglutide treatment. Liraglutide ameliorated CAV and cardiac fibrosis with reduced inflammatory cell infiltration and downregulated expression of adhesion molecules. Liraglutide inhibited EndMT in allografts and attenuated EndMT by inhibiting Smad3 activation in transforming growth factor-beta 1-treated human coronary artery endothelial cells. CONCLUSIONS: Administration of liraglutide from the time of transplantation upregulated GLP-1R in the transplanted heart and reduced cardiac fibrosis, inflammation, and CAV development. Therefore, liraglutide may be a novel therapy for CAV.
Asunto(s)
Receptor del Péptido 1 Similar al Glucagón/agonistas , Insuficiencia Cardíaca/tratamiento farmacológico , Insuficiencia Cardíaca/cirugía , Trasplante de Corazón , Liraglutida/farmacología , Enfermedades Vasculares/tratamiento farmacológico , Animales , Vasos Coronarios/patología , Modelos Animales de Enfermedad , Células Endoteliales/citología , Fibrosis , Glucosa/metabolismo , Antígenos de Histocompatibilidad Clase II/metabolismo , Humanos , Hipoglucemiantes/farmacología , Inmunohistoquímica , Terapia de Inmunosupresión , Inmunosupresores/uso terapéutico , Inflamación , Masculino , Ratones , Ratones Endogámicos C57BL , Proteína smad3/metabolismoRESUMEN
Myocarditis can be caused by several infectious and noninfectious causes. Treatment for myocarditis is still a difficult task in clinical practice. The gut microbiota is related to cardiovascular diseases such as atherosclerosis and hypertension. However, little is known about the role of the gut microbiota in myocarditis. In our study, we tested the hypothesis that gut dysbiosis is associated with myocarditis. We focused on whether fecal microbiota transplantation (FMT) can be used as an effective treatment for myocarditis. We used an experimental autoimmune myocarditis (EAM) mouse model. Fecal samples were isolated from the control and EAM groups for bacterial genome analysis. We observed an increase in microbial richness and diversity in the myocarditis mice. These changes were accompanied by an increased Firmicutes/Bacteroidetes ratio. We also evaluated the efficacy of FMT for the treatment of myocarditis. EAM mouse guts were repopulated with fecal contents from an untreated male mouse donor. We found that myocardial injury was improved by diminished inflammatory infiltration, showing that IFN-γ gene expression in the heart tissue and CD4+IFN-γ+ cells in the spleen were decreased after FMT in EAM mice. We also found that FMT was able to rebalance the gut microbiota by restoring the Bacteroidetes population and reshaping the microbiota composition. Myocarditis is associated with gut microbiota dysbiosis and characterized by an increased F/B ratio. FMT treatment can rebalance the gut microbiota and attenuate myocarditis. Thus, FMT may be a potential therapeutic strategy for the treatment of myocarditis.
Asunto(s)
Disbiosis/terapia , Trasplante de Microbiota Fecal , Miocarditis/terapia , Animales , Disbiosis/microbiología , Disbiosis/patología , Masculino , Ratones Endogámicos BALB C , Microbiota , Miocarditis/microbiología , Miocarditis/patología , Miocardio/patologíaRESUMEN
Renal fibrosis is recognized as the common route of all chronic kidney disease (CKD) progressing to end-stage renal disease (ESRD). Additionally, accumulating evidence suggests that epithelial-mesenchymal transition (EMT) plays a significant role in the process of renal fibrogenesis. Liraglutide is a long-acting glucagon-like peptide-1 (GLP-1) analog that has been widely used to treat type 2 diabetes. Recent studies have demonstrated that the GLP-1 analogs could also exert protective effects in cardiac fibrosis models. However, the effects of liraglutide on the progression of CKD remain largely unknown. In the present study, we investigated the effects of liraglutide on the progression to renal fibrosis induced by unilateral ureteral obstruction (UUO) and EMT of rat renal tubular epithelial cells (NRK-52E) induced with recombinant transforming growth factor-beta 1 (TGF-ß1). The results indicated that UUO increased collagen deposition and the mRNA expression of fibronectin (FN) and collagen type I alpha 1 (Col1α1) in the obstructed kidney tissues. The effects were blunted in liraglutide-treated UUO mice compared with control mice. The upregulation of Snail1 and alpha smooth muscle actin (α-SMA), and downregulation of E-cadherin revealed that EMT occurred in the UUO kidneys, and these effects were ameliorated following liraglutide treatment. Additionally, liraglutide treatment decreased the expression of TGF-ß1 and its receptor (TGF-ß1R) and inhibited the activation of its downstream signaling molecules (pSmad3 and pERK1/2). The in vitro results showed that the EMT and extracellular matrix (ECM) secretion of NRK-52E cells were induced by TGF-ß1. In addition, the Smad3 and ERK1/2 signaling pathways were highly activated in cells cultured with TGF-ß1. All these effects were attenuated by liraglutide treatment. However, the protective effects of liraglutide were abolished by co-incubation of the GLP-1 receptor (GLP-1R) antagonist exendin-3 (9-39). These results suggest that liraglutide attenuates the EMT and ECM secretion of NRK-52E cells induced by TGF-ß1 and EMT and renal fibrosis induced by UUO. The potential mechanism involves liraglutide binding to and activating GLP-1R, which prevents EMT by inhibiting the activation of TGF-ß1/Smad3 and ERK1/2 signaling pathways, thereby decreasing the ECM secretion and deposition. Therefore, liraglutide is a promising therapeutic agent that may halt the progression of renal fibrosis.
Asunto(s)
Hipoglucemiantes/uso terapéutico , Riñón/efectos de los fármacos , Riñón/patología , Liraglutida/uso terapéutico , Obstrucción Ureteral/tratamiento farmacológico , Animales , Línea Celular , Colágeno/análisis , Colágeno/metabolismo , Transición Epitelial-Mesenquimal/efectos de los fármacos , Fibrosis , Péptido 1 Similar al Glucagón/análogos & derivados , Péptido 1 Similar al Glucagón/uso terapéutico , Riñón/metabolismo , Masculino , Ratones Endogámicos C57BL , Ratas , Transducción de Señal/efectos de los fármacos , Obstrucción Ureteral/complicaciones , Obstrucción Ureteral/metabolismo , Obstrucción Ureteral/patologíaRESUMEN
AIMS: In this study, we aimed to clinically and genetically characterize LVNC patients and investigate the prevalence of variants in known and novel LVNC disease genes. INTRODUCTION: Left ventricular non-compaction cardiomyopathy (LVNC) is an increasingly recognized cause of heart failure, arrhythmia, thromboembolism, and sudden cardiac death. We sought here to dissect its genetic causes, phenotypic presentation and outcome. METHODS AND RESULTS: In our registry with follow-up of in the median 61 months, we analysed 95 LVNC patients (68 unrelated index patients and 27 affected relatives; definite familial LVNC = 23.5%) by cardiac phenotyping, molecular biomarkers and exome sequencing. Cardiovascular events were significantly more frequent in LVNC patients compared with an age-matched group of patients with non-ischaemic dilated cardiomyopathy (hazard ratio = 2.481, P = 0.002). Stringent genetic classification according to ACMG guidelines revealed that TTN, LMNA, and MYBPC3 are the most prevalent disease genes (13 patients are carrying a pathogenic truncating TTN variant, odds ratio = 40.7, Confidence interval = 21.6-76.6, P < 0.0001, percent spliced in 76-100%). We also identified novel candidate genes for LVNC. For RBM20, we were able to perform detailed familial, molecular and functional studies. We show that the novel variant p.R634L in the RS domain of RBM20 co-segregates with LVNC, leading to titin mis-splicing as revealed by RNA sequencing of heart tissue in mutation carriers, protein analysis, and functional splice-reporter assays. CONCLUSION: Our data demonstrate that the clinical course of symptomatic LVNC can be severe. The identified pathogenic variants and distribution of disease genes-a titin-related pathomechanism is found in every fourth patient-should be considered in genetic counselling of patients. Pathogenic variants in the nuclear proteins Lamin A/C and RBM20 were associated with worse outcome.
Asunto(s)
Hipertrofia Ventricular Izquierda/genética , Mutación/genética , Adulto , Arritmias Cardíacas/genética , Cardiomiopatía Dilatada/genética , Conectina/genética , Muerte Súbita Cardíaca/etiología , Femenino , Predisposición Genética a la Enfermedad/genética , Humanos , Lamina Tipo A/genética , Masculino , Linaje , Proteínas de Unión al ARN/genéticaRESUMEN
AIMS: Monocytes/macrophages response plays a key role in post-infarction inflammation that contributes greatly to post-infarction ventricular remodelling and cardiac rupture. Therapeutic targeting of the GABAA receptor, which is enriched in monocytes/macrophages but not expressed in the myocardium, may be possible after myocardial infarction (MI). METHODS AND RESULTS: After MI was induced by ligation of the coronary artery, C57BL/6 mice were intraperitoneally administered with one specific agonist or antagonist of the GABAA receptor (topiramate or bicuculline), in the setting of presence or depletion of monocytes/macrophages. Our data showed that within the first 2 weeks after MI, when monocytes/macrophages dominated, in contrast with bicuculline, topiramate treatment significantly reduced Ly-6Chigh monocyte numbers by regulating splenic monocytopoiesis and promoted foetal derived macrophages preservation and conversion of M1 to M2 or Ly-6Chigh to Ly-6Clow macrophage phenotype in the infarcted heart, though GABAAergic drugs failed to affect M1/M2 or Ly-6Chigh/Ly-6Clow macrophage polarization directly. Accordingly, pro-inflammatory activities mediated by M1 or Ly-6Chigh macrophages were decreased and reparative processes mediated by M2 or Ly-6Clow macrophages were augmented. As a result, post-infarction ventricular remodelling was attenuated, as reflected by reduced infarct size and increased collagen density within infarcts. Echocardiographic indices, mortality and rupture rates were reduced. After depletion of monocytes/macrophages by clodronate liposomes, GABAAergic drugs exhibited no effect on cardiac dysfunction and surrogate clinical outcomes. CONCLUSION: Control of the GABAA receptor activity in monocytes/macrophages can potently modulate post-infarction inflammation. Topiramate emerges as a promising drug, which may be feasible to translate for MI therapy in the future.
Asunto(s)
Antiinflamatorios/farmacología , Fructosa/análogos & derivados , Agonistas del GABA/farmacología , Ventrículos Cardíacos/efectos de los fármacos , Macrófagos/efectos de los fármacos , Monocitos/efectos de los fármacos , Infarto del Miocardio/tratamiento farmacológico , Miocarditis/prevención & control , Receptores de GABA/efectos de los fármacos , Animales , Antígenos Ly/metabolismo , Colágeno/metabolismo , Modelos Animales de Enfermedad , Fibrosis , Fructosa/farmacología , Rotura Cardíaca Posinfarto/metabolismo , Rotura Cardíaca Posinfarto/fisiopatología , Rotura Cardíaca Posinfarto/prevención & control , Ventrículos Cardíacos/metabolismo , Ventrículos Cardíacos/patología , Ventrículos Cardíacos/fisiopatología , Macrófagos/metabolismo , Ratones Endogámicos C57BL , Monocitos/metabolismo , Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología , Infarto del Miocardio/fisiopatología , Miocarditis/metabolismo , Miocarditis/patología , Miocarditis/fisiopatología , Miocardio/metabolismo , Miocardio/patología , Fenotipo , Receptores de GABA/metabolismo , Receptores de GABA-A/efectos de los fármacos , Receptores de GABA-A/metabolismo , Factores de Tiempo , Topiramato , Disfunción Ventricular Izquierda/metabolismo , Disfunción Ventricular Izquierda/fisiopatología , Disfunción Ventricular Izquierda/prevención & control , Función Ventricular Izquierda/efectos de los fármacos , Remodelación Ventricular/efectos de los fármacosRESUMEN
BACKGROUND: Atherosclerosis (AS) is a chronic inflammation characterized by massive infiltration of inflammatory cells in arterial wall plaques. Programmed death ligand-1 (PD-L1), a co-stimulatory molecule, plays a vital role in regulating immune responses. We investigated the role and mechanisms of PD-L1 expressed on oxidized low-density lipoprotein (ox-LDL)-impaired human umbilical vein endothelial cells (HUVECs) in promoting activation and cytokine production of CD4(+)CD25(+) forkhead box P3 (FoxP3) regulatory T cells (Tregs). METHODS AND RESULTS: Tregs were incubated alone, with HUVECs or HUVECs pre-stimulated with ox-LDL in the presence of anti-CD3 monoclonal antibodies (mAbs) for 48 h. HUVECs were shown to upregulate the immune phenotypic markers of Tregs, such as glucocorticoid-induced TNF receptor (GITR), cytotoxic T lymphocyte antigen-4 (CTLA-4) and programmed cell death-1 protein (PD-1). Moreover, HUVECs modulated cytokine production of Tregs (e.g., interleukin-10 (IL-10) and transforming growth factor-ß1 (TGF-ß1)). HUVECs treated with anti-PD-L1 mAbs were unable to regulate the surface expression and cytokine production of Tregs. The Transwell culture system suggested that interaction between HUVECs and Tregs via PD-L1 requires cell-to-cell contact. CONCLUSION: Expression of the negative co-stimulatory molecule PD-L1 on HUVECs may upregulate the inhibitory activation and cytokine production of CD4(+)CD25(+)Foxp3(+) regulatory T cells in AS.
Asunto(s)
Aterosclerosis/inmunología , Linfocitos T CD4-Positivos/inmunología , Factores de Transcripción Forkhead/inmunología , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Subunidad alfa del Receptor de Interleucina-2/inmunología , Receptor de Muerte Celular Programada 1/genética , Linfocitos T Reguladores/inmunología , Adolescente , Adulto , Aterosclerosis/metabolismo , Aterosclerosis/patología , Antígenos CD4/inmunología , Antígenos CD4/metabolismo , Células Cultivadas , Ensayo de Inmunoadsorción Enzimática , Femenino , Citometría de Flujo , Factores de Transcripción Forkhead/metabolismo , Células Endoteliales de la Vena Umbilical Humana/inmunología , Células Endoteliales de la Vena Umbilical Humana/patología , Humanos , Inmunidad Celular , Subunidad alfa del Receptor de Interleucina-2/metabolismo , Masculino , Receptor de Muerte Celular Programada 1/biosíntesis , Linfocitos T Reguladores/patología , Adulto JovenRESUMEN
OBJECTIVE: Coronary heart disease (CHD) is associated with high morbidity and mortality worldwide. CD4âºCD25âºFOXP3⺠regulatory T cells (Tregs) play a role in the modulation of vascular inflammation. The negatively costimulatory molecule programmed cell death ligand 1 (PD-L1) exerts a prominent effect on the adjustment of immune responses. We investigated the relationship between the expression of PD-L1 on peripheral blood Tregs and the severity of CHD. METHODS AND RESULTS: Human peripheral blood was collected from 59 patients with CHD and 11 healthy volunteers. The expression of PD-L1 on peripheral blood Tregs was detected by flow cytometry, and the production of interleukin 2 (IL-2), IL-4, IL-10, and transforming growth factor ß1 in plasma was determined using enzyme-linked immunosorbent assay. The subgroup of patients with acute coronary syndrome (ACS), which includes unstable angina pectoris, non-ST-segment elevation myocardial infarction, and ST-segment elevation myocardial infarction, showed a significant reduction of FOXP3 and PD-L1 expression on Tregs compared with the subgroup of patients with chronic coronary artery disease, comprising stable angina pectoris, silent myocardial ischemia, and ischemic heart failure, and the control group. Moreover, the ACS group showed significantly increased production of IL-2, and decreased production of IL-4, IL-10, and transforming growth factor ß1, compared with the coronary artery disease and control groups. CONCLUSION: Expression of the coinhibitory molecule PD-L1 on peripheral blood Tregs is correlated negatively with the severity of CHD and could serve as a novel indicator of ACS.
Asunto(s)
Síndrome Coronario Agudo/metabolismo , Angina Estable/metabolismo , Angina Inestable/metabolismo , Antígeno B7-H1/metabolismo , Enfermedad de la Arteria Coronaria/metabolismo , Factores de Transcripción Forkhead/metabolismo , Infarto del Miocardio/metabolismo , Linfocitos T Reguladores/metabolismo , Síndrome Coronario Agudo/inmunología , Anciano , Angina Estable/inmunología , Angina Inestable/inmunología , Antígeno B7-H1/inmunología , Proteína C-Reactiva/inmunología , Antígenos CD4/metabolismo , Estudios de Casos y Controles , Enfermedad de la Arteria Coronaria/inmunología , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Interleucina-10/inmunología , Interleucina-2/inmunología , Subunidad alfa del Receptor de Interleucina-2/metabolismo , Interleucina-4/inmunología , Masculino , Persona de Mediana Edad , Infarto del Miocardio/inmunología , Isquemia Miocárdica/inmunología , Isquemia Miocárdica/metabolismo , Linfocitos T Reguladores/inmunología , Factor de Crecimiento Transformador beta1/inmunologíaRESUMEN
This study was aimed to establish an experimental mouse model of combined transgenic inhibition of both multifunctional Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and inward rectifier potassium current (Ik1), and to observe whether the specific inhibition of both CaMKII and Ik1 can bring about any effects on cardiac remodeling. Mice were divided into 4 groups: wild type (WT), CaMKII inhibited (AC3-I), Ik1 inhibited (Kir2.1-AAA) and combined inhibition of both CaMKII and Ik1 (AC3-I+Kir2.1-AAA). Mice in each group received electrocardiogram (ECG) and echocardiography examination. ECG in the condition of isoproterenol (ISO) injection was also checked. The whole cell patch clamp technique was used to measure Ik1 and the transient outward potassium current (Ito) from enzymatically isolated myocytes of left ventricle. In the condition of basal status, no significant changes of heart rate, PR interval and QRS interval were observed. No mouse showed ventricular arrhythmias in all of the 4 groups. After ISO injection, each group presented no significant ventricular arrhythmias either. The indexes measured by M-mode (motion-mode) and two-dimensional echocardiography had no significant differences among the four groups. Ik1 in AC3-I group was significantly higher than those in other three groups (P < 0.01) because of the results brought about by CaMKII inhibition. Among the latter three groups, both Kir2.1-AAA group and AC3-I+Kir2.1-AAA group had a significant reduced Ik1 compared with that of WT group, which was due to the Ik1 inhibition (P < 0.01). Ito in AC3-I group was higher than that of the other three groups (P < 0.01), but there were no significant differences in Ito among WT, Kir2.1-AAA and AC3-I+Kir2.1-AAA groups. Thus, combined transgenic myocardial CaMKII and Ik1 inhibition eliminated the up-regulation of Ik1 in CaMKII inhibited mice, and had no effects on cardiac remodeling including heart structure and function as well as arrhythmias at the basic and ISO conditions. The results of this study may provide a basis for the further investigation of combined inhibition of CaMKII and Ik1 in pathogenic cardiac remodeling.
Asunto(s)
Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/fisiología , Corazón/fisiología , Canales de Potasio de Rectificación Interna/fisiología , Remodelación Ventricular , Animales , Arritmias Cardíacas , Síndrome de Brugada , Trastorno del Sistema de Conducción Cardíaco , Modelos Animales de Enfermedad , Electrocardiografía , Sistema de Conducción Cardíaco/anomalías , Ventrículos Cardíacos , Isoproterenol , Ratones , Ratones Transgénicos , Técnicas de Placa-Clamp , Regulación hacia ArribaRESUMEN
OBJECTIVE: Proinflammatory cytokine TNF-α during MI/R injury has been studied extensively. However, how TNF-α induces microvascular dysfunction in MI/R is still unclear. This study investigates whether TNF-α regulates fibrinogen-like protein 2 (fgl2) expression, a procoagulant resulting in the formation of fibrin-rich microthrombus in MI/R injury. METHODS AND RESULTS: Microthrombosis, TNF-α and fgl2 expression were assessed in rats with MI/R injury. The effect of TNF-α on fgl2 expression and fgl2 prothrombinase activity was investigated in CMECs, then CMECs were pretreated with selective inhibitors of NF-κB and p38 MAPK pathways. TNF-α and fgl2 expression were both upregulated in MI/R group. When neutralization of TNF-α, fgl2 expression was decreased in vivo. Fgl2 expression was upregulated in CMECs exposed to TNF-α. Accordingly, the ability of thrombin generation was increased in CMECs. Besides, TNF-α-induced fgl2 expression in the cells was suppressed by NF-κB inhibitor PDTC and/or p38 MAPK inhibitor SB203580. CONCLUSION: TNF-α upregulates fgl2 expression via activation of NF-kB and p38 MAPK in CMECs. TNF-α-induced flg2 in CMECs mediates the formation of fibrin-rich microthrombus, which may be one of the mechanisms of microvascular dysfunction or obstruction due to MI/R injury.
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Células Endoteliales/metabolismo , Fibrinógeno/biosíntesis , Daño por Reperfusión Miocárdica/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Regulación hacia Arriba , Animales , Células Cultivadas , Células Endoteliales/patología , Daño por Reperfusión Miocárdica/patología , FN-kappa B/metabolismo , Ratas , Ratas Sprague-Dawley , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
Cholesterol-metabolism-associated molecules, including scavenger receptor class A (SR-A), lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), CD36, ACAT1, ABCA1, ABCG1, and scavenger receptor class B type I, can modulate cholesterol metabolism in the transformation from macrophages to foam cells. Voltage-gated potassium channel Kv1.3 has increasingly been demonstrated to play an important role in the modulation of macrophage function. Here, we investigate the role of Kv1.3 in modulating cholesterol-metabolism-associated molecules in human acute monocytic leukemia cell-derived macrophages (THP-1 macrophages) and human monocyte-derived macrophages exposed to oxidized LDL (ox-LDL). Human Kv1.3 and Kv1.5 channels (hKv1.3 and hKv1.5) are expressed in macrophages and form a heteromultimeric channel. The hKv1.3-E314 antibody that we had generated as a specific hKv1.3 blocker inhibited outward delayed rectifier potassium currents, whereas the hKv1.5-E313 antibody that we had generated as a specific hKv1.5 blocker failed. Accordingly, the hKv1.3-E314 antibody reduced percentage of cholesterol ester and enhanced apoA-I-mediated cholesterol efflux in THP-1 macrophages and human monocyte-derived macrophages exposed to ox-LDL. The hKv1.3-E314 antibody downregulated SR-A, LOX-1, and ACAT1 expression and upregulated ABCA1 expression in THP-1 macrophages and human monocyte-derived macrophages. Our results reveal that specific Kv1.3 blockade represents a novel strategy modulating cholesterol metabolism in macrophages, which benefits the treatment of atherosclerotic lesions.
Asunto(s)
Especificidad de Anticuerpos , Colesterol/metabolismo , Canal de Potasio Kv1.3/antagonistas & inhibidores , Canal de Potasio Kv1.3/inmunología , Lipoproteínas LDL/farmacología , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Transportador 1 de Casete de Unión a ATP , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 1 , Transportadoras de Casetes de Unión a ATP/metabolismo , Acetil-CoA C-Acetiltransferasa/metabolismo , Apolipoproteína A-I/metabolismo , Transporte Biológico/efectos de los fármacos , Antígenos CD36/metabolismo , Línea Celular , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Fenómenos Electrofisiológicos/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Canal de Potasio Kv1.3/metabolismo , Canal de Potasio Kv1.5/antagonistas & inhibidores , Canal de Potasio Kv1.5/inmunología , Canal de Potasio Kv1.5/metabolismo , Macrófagos/citología , Monocitos/citología , Potasio/metabolismo , Receptores Depuradores de Clase A/metabolismo , Receptores Depuradores de Clase E/metabolismoRESUMEN
Curcumin, the principal active component of turmeric, has long been used to treat various diseases in India and China. Recent studies show that curcumin can serve as a therapeutic agent for autoimmune diseases via a variety of mechanisms. Effector memory T cells (T(EM), CCR7⻠CD45RO⺠T lymphocyte) have been demonstrated to play a crucial role in the pathogenesis of T cell-mediated autoimmune diseases, such as multiple sclerosis (MS) or rheumatoid arthritis (RA). Kv1.3 channels are predominantly expressed in T(EM) cells and control T(EM) activities. In the present study, we examined the effect of curcumin on human Kv1.3 (hKv1.3) channels stably expressed in HEK-293 cells and its ability to inhibit proliferation and cytokine secretion of T(EM) cells isolated from patients with MS or RA. Curcumin exhibited a direct blockage of hKv1.3 channels in a time-dependent and concentration-dependent manner. Moreover, the activation curve was shifted to a more positive potential, which was consistent with an open-channel blockade. Paralleling hKv1.3 inhibition, curcumin significantly inhibited proliferation and interferon-γ secretion of T(EM) cells. Our findings demonstrate that curcumin is able to inhibit proliferation and proinflammatory cytokine secretion of T(EM) cells probably through inhibition of hKv1.3 channels, which contributes to the potency of curcumin for the treatment of autoimmune diseases. This is probably one of pharmacological mechanisms of curcumin used to treat autoimmune diseases.
Asunto(s)
Curcumina/farmacología , Memoria Inmunológica/efectos de los fármacos , Canal de Potasio Kv1.3/antagonistas & inhibidores , Linfocitos T/inmunología , Artritis Reumatoide/inmunología , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta Inmunológica , Células HEK293 , Humanos , Interferón gamma/inmunología , Esclerosis Múltiple/inmunología , Linfocitos T/efectos de los fármacosRESUMEN
Regulatory T (Treg) cells play a protective role against the development of atherosclerosis. Previous studies have revealed Treg cell defects in patients with non-ST elevation acute coronary syndrome (NSTACS), but the mechanisms underlying these defects remain unclear. In this study, we found that the numbers of peripheral blood CD4(+)CD25(+)CD127(low) Treg cells and CD4(+)CD25(+)CD127(low)CD45RA(+)CD45RO(-) naive Treg cells were lower in the NSTACS patients than in the chronic stable angina (CSA) and the chest pain syndrome (CPS) patients. However, the number of CD4(+)CD25(+)CD127(low)CD45RA(-)CD45RO(+) memory Treg cells was comparable in all of the groups. The frequency of CD4(+)CD25(+)CD127(low)CD45RO(-)CD45RA(+)CD31(+) recent thymic emigrant Treg cells and the T cell receptor excision circle content of purified Treg cells were lower in the NSTACS patients than in the CSA patients and the CPS controls. The spontaneous apoptosis of Treg cells (defined as CD4(+)CD25(+)CD127(low)annexin V(+)7-AAD(-)) was increased in the NSTACS patients compared with the CSA and CPS groups. Furthermore, oxidized LDL could induce Treg cell apoptosis, and the oxidized LDL levels were significantly higher in the NSTACS patients than in the CSA and CPS groups. In accordance with the altered Treg cell levels, the concentration of TNF-α was increased in the NSTACS patients, resulting in a decreased IL-10/TNF-α ratio. These findings indicate that the impaired thymic output of Treg cells and their enhanced susceptibility to apoptosis in the periphery were responsible for Treg cell defects observed in the NSTACS patients.
Asunto(s)
Síndrome Coronario Agudo/sangre , Apoptosis , Linfocitos T Reguladores/metabolismo , Timo/metabolismo , Síndrome Coronario Agudo/genética , Síndrome Coronario Agudo/inmunología , Anciano , Antígenos CD/sangre , Antígenos CD/inmunología , Transporte Biológico/inmunología , Femenino , Humanos , Interleucina-11/sangre , Interleucina-11/inmunología , Lipoproteínas LDL/sangre , Lipoproteínas LDL/inmunología , Masculino , Persona de Mediana Edad , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/patología , Timo/inmunología , Timo/patología , Factor de Necrosis Tumoral alfa/sangre , Factor de Necrosis Tumoral alfa/inmunologíaRESUMEN
OBJECTIVE: To investigate effects of supplementation of folate on the expression of monocyte chemoattractant protein-1 (MCP-1) in aortic endothelium and release from peripheral blood mononuclear cells (PBMC) in rats with hyperhomocysteinemia induced by ingestion of excess methionine. METHODS: Thirty male SD rats were randomly divided into 3 groups (n = 10 for each group): control group (Control), high homocysteinemia group (Hhcy), and folate supplementation group (FA). They were fed with nomal diet, normal diet enriched by 1.7% methionine, and normal diet plus 1.7% methionine and 0.006% folate, respectively, for 45 days. The levels of total plasma homocysteine (Thcy) were measured by high performance liquid chromatography and the concentrations of chemokine MCP-1 released from PBMC stimulated by oxidized low density lipoprotein were detected by enzyme immunoassays. The expression of MCP-1 on aortas of rats was detected by immunohistochemistry and Western blot. RESULTS: A high methionine diet for 45 days induced hyperhomocysteinemia. Folate supplementation to high-methionine diet significantly decreased plasma Thcy levels (P < 0.01). The expression of MCP-1 in aortic endothelium and the levels of MCP-1 released from PBMC stimulated by oxidized low density lipoprotein were significantly higher in rats of Hhcy group than in rats of control group (P < 0.05, P < 0.01). During supplementation of folate, normalization of Thcy levels was accompanied by a marked reduction of MCP-1 expression in aortic endothelium and by a significant decrease of MCP-1 released from PBMC stimulated by oxidized low density lipoprotein (P < 0.05, P < 0.01). CONCLUSION: Folate supplementation can prevent an elevation of homocysteine levels in the blood and decrease the expression MCP-1 in aortic endothelium and release of MCP-1 from PBMC in rats with hyperhomocysteinemia.
Asunto(s)
Quimiocina CCL2/biosíntesis , Ácido Fólico/farmacología , Hiperhomocisteinemia/metabolismo , Animales , Aorta/citología , Aorta/metabolismo , Quimiocina CCL2/genética , Endotelio Vascular/metabolismo , Homocisteína/sangre , Hiperhomocisteinemia/sangre , Hiperhomocisteinemia/inducido químicamente , Leucocitos Mononucleares/metabolismo , Masculino , Metionina , Distribución Aleatoria , Ratas , Ratas Sprague-DawleyRESUMEN
UNLABELLED: Background- Polymorphisms in the promoter (T-786C) and exon 7 (G894T) of the endothelial nitric oxide synthase (eNOS) gene were shown to be associated with reduced vascular NO production or increased proteolytic cleavage of eNOS. Therefore, we aimed to determine the effects of these polymorphisms on endothelial function and endothelial response to physical exercise in patients with coronary artery disease (CAD). METHODS AND RESULTS: Sixty-seven patients were randomized to either a training or a control group. At the beginning and after 4 weeks, acetylcholine-induced changes in average peak velocity (APV) of a coronary or mammary artery were invasively assessed by Doppler velocimetry. Polymorphisms were detected by polymerase chain reaction-restriction fragment length polymorphism. At the beginning, in subjects with the wild-type (WT) variant, APV increased by 88+/-7% in response to acetylcholine. This response was significantly blunted in patients who were positive for the promoter (44+/-7%) or the exon 7 (62+/-9%) polymorphism. Four weeks of exercise training resulted in augmentation of an endothelium-dependent increase in APV by +36+/-12% in promoter polymorphism-positive patients but by +81+/-18% and +91+/-15% in WT variant- and exon 7 polymorphism-positive subjects, respectively. CONCLUSIONS: These results suggest that the presence of either one of the polymorphisms attenuates endothelium-dependent vasodilatation in CAD patients. Only the promoter polymorphism might have an adverse effect on training-induced improvement in endothelial function.