RESUMEN
BACKGROUND: Target lumen enlargement (TLE) or "late lumen enlargement" is often encountered after percutaneous coronary intervention (PCI) with drug-coated balloons (DCB). To date, the prognosis of coronary arterial lesions with or without TLE has not been clearly elucidated. AIMS: This study aimed to assess the long-term prognosis of coronary arterial lesions with or without TLE observed within 1 year (early TLE) after DCB angioplasty using serial quantitative angiographic follow-up. METHODS: One hundred and ninety-three consecutive patients (de novo coronary arterial lesions, 251) who underwent follow-up angiography within 1 year after DCB angioplasty (early follow-up, median: 6 months) were retrospectively evaluated. Of these, 97 patients (125 lesions) also underwent angiography more than 1 year after DCB angioplasty (late follow-up, median: 37 months). TLE was defined as an increase in minimal lumen diameter (MLD) after PCI at each follow-up. RESULTS: Early TLE was detected in 142 lesions (56.6%). Of these, 76 lesions were also evaluated at late follow-up. TLE persisted even at late follow-up in 67 of the 76 lesions (88.2%). An increase in MLD in early TLE (+) lesions was observed in the period between post-PCI and early follow-up (1.84 ± 0.06 vs. 2.12 ± 0.07 mm, p < 0.001) but not between early and late follow-up (2.12 ± 0.07 vs. 2.16 ± 0.07 mm, p = 0.74). In contrast, 49 of 109 lesions without early TLE were evaluated at late follow-up, of which 28 lesions (57.1%) showed TLE at late follow-up. The MLD of early TLE (-) lesions (n = 49) significantly increased from early (1.63 ± 0.061 mm) to late follow-up (1.84 ± 0.06 mm) (p < 0.001). No aneurysms were found in any of these cases. CONCLUSION: Early TLE was observed in more than half of the lesions, with the majority remaining at late follow-up. Alternatively, half of the lesions without early TLE showed late TLE, occurring biphasically after DCB angioplasty.
Asunto(s)
Angioplastia Coronaria con Balón , Enfermedad de la Arteria Coronaria , Reestenosis Coronaria , Intervención Coronaria Percutánea , Humanos , Enfermedad de la Arteria Coronaria/cirugía , Estudios Retrospectivos , Angiografía Coronaria , Resultado del Tratamiento , Materiales Biocompatibles RevestidosRESUMEN
OBJECTIVES: This study sought to assess the efficacy of oversized drug-coated balloon (DCB) inflation at low pressure for the prevention of acute dissections and late restenosis. BACKGROUND: The major limitation of DCB coronary angioplasty is the occurrence of severe dissection after inflation of DCB. METHODS: Between 2014 and 2018, 273 consecutive patients were retrospectively studied. 191 lesions (154 patients) treated by oversized DCB inflation at low pressure (<4 atm, 2.4 ± 1.2 atm, DCB/artery ratio 1.14 ± 0.22; LP group) were compared with 135 lesions (119 patients) treated by the standard DCB technique (7.1 ± 2.2 atm, DCB/artery ratio 1.03 ± 0.16; SP group). RESULTS: Although the lesions in the LP group were more complex than those in the SP group (smaller reference diameter (2.38 mm vs. 2.57 mm, P=0.011), longer lesions (11.7 mm vs. 10.5 mm, P=0.10), and more frequent use of rotational atherectomy (45.0% vs. 28.1%, P=0.003), there was no significant difference in the NHLBI type of dissections between the two groups (11.5%, 12.0%, 5.2% vs. 12.6%, 12.6%, 2.2% in type A, B, and C, P=0.61), and no bailout stenting was required. In 125 well-matched lesion pairs after propensity score analysis, the cumulative incidence of target lesion revascularization at 3 years was 4.5% vs. 7.0%, respectively (P=0.60). Late lumen loss (-0.00 mm vs. -0.01 mm, P=0.94) and restenosis rates (7.4% vs. 7.1%, P=1.0) were similar in both of the groups. CONCLUSION: The application of oversized DCB at low pressure is effective and feasible for preventing late restenosis comparative to the standard technique of DCB.
Asunto(s)
Angioplastia Coronaria con Balón , Materiales Biocompatibles Revestidos/farmacología , Enfermedad de la Arteria Coronaria/cirugía , Diseño de Equipo , Cuidados Intraoperatorios/métodos , Anciano , Angioplastia Coronaria con Balón/efectos adversos , Angioplastia Coronaria con Balón/instrumentación , Angioplastia Coronaria con Balón/métodos , Fármacos Cardiovasculares/farmacología , Femenino , Humanos , Masculino , Estudios Retrospectivos , Resultado del Tratamiento , Dispositivos de Acceso VascularRESUMEN
Activation of Fas signaling is a key mediator of doxorubicin cardiotoxicity, which involves both cardiomyocyte apoptosis and myocardial inflammation. In this study, acute cardiotoxicity was induced in mice by doxorubicin, and some mice simultaneously received an intramuscular injection of adenoviral vector encoding mouse soluble Fas (sFas) gene (Ad.CAG-sFas), an inhibitor of Fas/Fas ligand interaction. Two weeks later, left ventricular dilatation and dysfunction were apparent in the LacZ-treated control group, but both were significantly mitigated in the sFas-treated group. The in situ nick-end labeling-positive rate were similar in the two groups, and although electron microscopy revealed cardiomyocyte degeneration, no apoptotic structural features and no activation of caspases were detected, suggesting an insignificant role of apoptosis in this model. Instead, sFas treatment reversed doxorubicin-induced down-regulation of GATA-4 and attenuated ubiquitination of myosin heavy chain and troponin I to preserve these sarcomeric proteins. In addition, doxorubicin-induced significant leukocyte infiltration, fibrosis, and oxidative damage to the myocardium, all of which were largely reversed by sFas treatment. sFas treatment also suppressed doxorubicin-induced p53 overexpression, phosphorylation of c-Jun N-terminal kinase, c-Jun, and inhibitor of nuclear factor-kappaB, as well as production of cyclooxygenase-2 and monocyte chemoattractant protein-1, and it restored extracellular signal-regulated kinase activation. Therefore, sFas gene therapy prevents the progression of doxorubicin-induced acute cardiotoxicity, with accompanying attenuation of the cardiomyocyte degeneration, inflammation, fibrosis, and oxidative damage caused by Fas signaling.
Asunto(s)
Apoptosis/fisiología , Doxorrubicina , Terapia Genética/métodos , Cardiopatías/inducido químicamente , Cardiopatías/terapia , Receptor fas/genética , Animales , Apoptosis/genética , Daño del ADN/genética , Ecocardiografía , Fibrosis Endomiocárdica/genética , Fibrosis Endomiocárdica/patología , Fibrosis Endomiocárdica/prevención & control , Cardiopatías/genética , Cardiopatías/patología , Inflamación/genética , Inflamación/patología , Operón Lac , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Miocardio/patología , Miocardio/ultraestructura , Estrés Oxidativo/genética , Estrés Oxidativo/fisiología , Transducción de Señal/genética , Transducción de Señal/fisiología , Solubilidad , Receptor fas/antagonistas & inhibidoresRESUMEN
Granulocyte colony-stimulating factor (G-CSF) is a potent angiogenic factor. We hypothesized that G-CSF-immersed gelatin hydrogel microspheres (G-CSF-GHMs) injected into the ischemic legs might continuously release a small amount of G-CSF to locally stimulate angiogenesis without unfavorable systemic effects. Just after ligation of the right femoral artery of BALB/c mice, recombinant human G-CSF (100-µg/kg)-immersed GHM was injected into the right hindlimb muscles; the controls included a saline-injected group, an intramuscularly injected G-CSF group, a subcutaneously injected G-CSG group, and an empty GHM-injected group. Eight weeks later, improvement of blood perfusion to the ischemic limb was significantly augmented in the G-CSF-GHM group compared with any of the control groups. Despite there being no increase in the serum concentration of G-CSF, in peripheral granulocytes, or in circulating endothelial progenitor cells, not only capillary but also arteriolar density was significantly increased in this group. Next, we started treatment with G-CSF-GHM 4 weeks after ligation to examine whether the treatment is effective if performed during the chronic stage of ischemia. The late treatment was also found to effectively improve blood flow in the ischemic leg. In conclusion, G-CSF-GHM administration is suggested to be a promising and readily usable approach to treating peripheral artery disease, applicable even during the chronic stage.
Asunto(s)
Factor Estimulante de Colonias de Granulocitos/farmacología , Isquemia/tratamiento farmacológico , Microesferas , Enfermedad Arterial Periférica/tratamiento farmacológico , Animales , Modelos Animales de Enfermedad , Gelatina/química , Factor Estimulante de Colonias de Granulocitos/administración & dosificación , Miembro Posterior/irrigación sanguínea , Miembro Posterior/efectos de los fármacos , Humanos , Hidrogeles , Inyecciones Intramusculares , Isquemia/patología , Masculino , Ratones , Ratones Endogámicos BALB C , Enfermedad Arterial Periférica/patología , Proteínas Recombinantes , Factores de TiempoRESUMEN
Although recanalization of the infarct-related artery late after myocardial infarction (MI) is known to reduce both cardiac remodeling and mortality, the mechanisms responsible are not yet fully understood. We compared infarcted rat hearts in which the infarct-related coronary artery was opened 24 hours after infarction (late reperfusion [LR] group) with those having a permanently occluded artery. Left ventricular dilatation and dysfunction were significantly mitigated in the LR group 1, 2, and 4 weeks post-MI. Attributable, in large part, to the greater number of cells present, the infarcted wall was significantly thicker in the LR group, which likely reduced wall stress and mitigated cardiac dysfunction. Granulation tissue cell proliferation was increased to a greater degree in the LR group 4 days post-MI, whereas the incidence of apoptosis was significantly lower throughout the subacute stage (4 days, 1 week, and 2 weeks post-MI), further suggesting preservation of granulation tissue cells contributes to the thick, cell-rich scar. Functionally, myocardial debris was more rapidly removed from the infarcted areas in the LR group during subacute stages, and stouter collagen was more rapidly synthesized in those areas. Direct acceleration of Fas-mediated apoptosis by hypoxia was confirmed in vitro using infarct tissue-derived myofibroblasts. In salvaged cardiomyocytes, degenerative changes, but not apoptosis, were mitigated in the LR group, accompanied by restoration of GATA-4 and sarcomeric protein expression. Along with various mechanisms proposed earlier, the present findings appear to provide an additional pathophysiological basis for the benefits of late reperfusion.
Asunto(s)
Infarto del Miocardio/fisiopatología , Reperfusión Miocárdica , Miocitos Cardíacos , Remodelación Ventricular , Animales , Apoptosis , Proteínas Portadoras/metabolismo , Colágeno/biosíntesis , Proteínas del Citoesqueleto , Fibroblastos/metabolismo , Fibroblastos/patología , Factor de Transcripción GATA4/metabolismo , Humanos , Masculino , Infarto del Miocardio/metabolismo , Infarto del Miocardio/mortalidad , Infarto del Miocardio/patología , Infarto del Miocardio/terapia , Reperfusión Miocárdica/métodos , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Ratas , Ratas Wistar , Factores de TiempoRESUMEN
The small leucine-rich proteoglycan decorin is a natural inhibitor of transforming growth factor-beta (TGF-beta) and exerts antifibrotic effects in heart and to stimulate skeletal muscle regeneration. We investigated decorin's chronic effects on postinfarction cardiac remodeling and dysfunction. Myocardial infarction (MI) was induced in mice by left coronary artery ligation. An adenoviral vector encoding human decorin (Ad. CAG-decorin) was then injected into the hindlimbs on day 3 post-MI (control, Ad.CAG-LacZ). Four weeks post-MI, the decorin-treated mice showed significant mitigation of the left ventricular dilatation and dysfunction seen in control mice. Although infarct size did not differ between the two groups, the infarcted wall thickness was greater and the segmental length of the infarct was smaller in decorin-treated mice. In addition, cellular components, including myofibroblasts and blood vessels, were more abundant within the infarcted area in decorin-treated mice, and fibrosis was significantly reduced in both the infarcted and noninfarcted areas of the left ventricular wall. Ten days post-MI, there was greater cell proliferation and less apoptosis among granulation tissue cells in the infarcted areas of decorin-treated mice. The treatment, however, did not affect proliferation and apoptosis of salvaged cardiomyocytes. Although decorin gene therapy did not affect TGF-beta1 expression in the infarcted heart, it inhibited Smad2/3 activation (downstream mediators of TGF-beta signaling). In summary, postinfarction decorin gene therapy mitigated cardiac remodeling and dysfunction by altering infarct tissue noncardiomyocyte dynamics and preventing cardiac fibrosis, accompanying inhibition of Smad2/3 activation.
Asunto(s)
Adenoviridae/genética , Proteínas de la Matriz Extracelular/biosíntesis , Terapia Genética , Vectores Genéticos , Hipertrofia Ventricular Izquierda/prevención & control , Infarto del Miocardio/terapia , Miocitos Cardíacos/metabolismo , Proteoglicanos/biosíntesis , Disfunción Ventricular Izquierda/prevención & control , Remodelación Ventricular , Animales , Apoptosis , Proliferación Celular , Enfermedad Crónica , Decorina , Modelos Animales de Enfermedad , Proteínas de la Matriz Extracelular/genética , Fibrosis , Células HeLa , Humanos , Hipertrofia Ventricular Izquierda/genética , Hipertrofia Ventricular Izquierda/metabolismo , Hipertrofia Ventricular Izquierda/fisiopatología , Masculino , Ratones , Ratones Endogámicos C57BL , Infarto del Miocardio/genética , Infarto del Miocardio/metabolismo , Infarto del Miocardio/fisiopatología , Miocitos Cardíacos/patología , Proteoglicanos/genética , Proteína Smad2/metabolismo , Proteína smad3/metabolismo , Factores de Tiempo , Transducción Genética , Transfección , Factor de Crecimiento Transformador beta1/metabolismo , Disfunción Ventricular Izquierda/genética , Disfunción Ventricular Izquierda/metabolismo , Disfunción Ventricular Izquierda/fisiopatologíaRESUMEN
1. In the present study, we examined the effects of inhibiting transforming growth factor (TGF)-beta in a mouse model of diabetic nephropathy. 2. An adenovirus harbouring the gene encoding soluble TGF-beta type II receptor (Ad.CAG-sTbetaRII), a competitive inhibitor of TGF-beta, was injected into hindlimb muscles (systemic delivery) of mice 5 weeks after the induction of diabetes with streptozotocin. The control group was injected with an adenovirus encoding the LacZ gene (Ad-LacZ). 3. Five weeks after administration, anti-TGF-beta gene therapy was found to have had no effect on renal function, albuminuria or glucose metabolism in mice with diabetic nephropathy. Nonetheless, this gene therapy did significantly reduce fibrosis in both glomeruli and renal tubules. These effects were accompanied by attenuation of the increased expression of alpha-smooth muscle actin normally seen in kidneys of diabetic mice and better preservation of glomerular cell numbers, although the thickness of the glomerular capillary basement membrane was unchanged. The plasma concentration of soluble TGF-beta type II receptor peaked on Day 7 after treatment, but was undetectable by Day 14. Moreover, a second treatment with Ad.CAG-sTbetaRII failed to prolong the interval of gene product expression in the blood. 4. The present anti-TGF-beta gene therapy showed a significant antifibrotic effect in a model of diabetic nephropathy, but failed to improve renal function. The inadequacy of the observed effect is likely due to the relatively short interval of gene product expression. This problem will have to be overcome if gene therapies for slowly progressing diseases, like diabetic nephropathy, are to be realised.
Asunto(s)
Adenoviridae/genética , Nefropatías Diabéticas/genética , Nefropatías Diabéticas/terapia , Modelos Animales de Enfermedad , Vectores Genéticos/administración & dosificación , Proteínas Serina-Treonina Quinasas/administración & dosificación , Proteínas Serina-Treonina Quinasas/genética , Receptores de Factores de Crecimiento Transformadores beta/administración & dosificación , Receptores de Factores de Crecimiento Transformadores beta/genética , Animales , Pollos , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/patología , Diabetes Mellitus Experimental/terapia , Nefropatías Diabéticas/patología , Femenino , Terapia Genética/métodos , Vectores Genéticos/genética , Humanos , Ratones , Ratones Endogámicos C57BL , Conejos , Receptor Tipo II de Factor de Crecimiento Transformador beta , Solubilidad , Factor de Crecimiento Transformador beta/antagonistas & inhibidoresRESUMEN
BACKGROUND: Doxorubicin is a highly effective antineoplastic drug, but its clinical use is limited by its adverse side effects on the heart. We investigated possible protective effects of erythropoietin against doxorubicin-induced cardiomyopathy. METHODS AND RESULTS: Cardiomyopathy was induced in mice by a single intraperitoneal injection of doxorubicin (15 mg/kg). In some cases, human recombinant erythropoietin (5000 U/kg) was started simultaneously. Two weeks later, left ventricular dilatation and dysfunction were apparent in mice given doxorubicin but were significantly attenuated by erythropoietin treatment. Erythropoietin also protected hearts against doxorubicin-induced cardiomyocyte atrophy and degeneration, myocardial fibrosis, inflammatory cell infiltration, and downregulation of expression of GATA-4 and 3 sarcomeric proteins, myosin heavy chain, troponin I, and desmin. Cyclooxygenase-2 expression was upregulated in doxorubicin-treated hearts, and that, too, was attenuated by erythropoietin. No doxorubicin-induced apoptotic effects were seen, nor were any changes seen in the expression of tumor necrosis factor-alpha or transforming growth factor-beta1. Antiatrophic and GATA-4 restoring effects of erythropoietin were demonstrated in the in vitro experiments with cultured cardiomyocytes exposed to doxorubicin, which indicated the direct cardioprotective effects of erythropoietin beyond erythropoiesis. Cardiac erythropoietin receptor expression was downregulated in doxorubicin-induced cardiomyopathy but was restored by erythropoietin. Among the downstream mediators of erythropoietin receptor signaling, activation of extracellular signal-regulated kinase was reduced by doxorubicin but restored by erythropoietin. By contrast, erythropoietin was ineffective when administered after cardiac dysfunction was established in the chronic stage. CONCLUSIONS: The present study indicates a protective effect of erythropoietin against doxorubicin-induced cardiomyopathy.
Asunto(s)
Cardiomiopatías/tratamiento farmacológico , Cardiomiopatías/prevención & control , Eritropoyetina/farmacología , Insuficiencia Cardíaca/tratamiento farmacológico , Insuficiencia Cardíaca/prevención & control , Animales , Antibióticos Antineoplásicos , Cardiomiopatías/inducido químicamente , Caspasa 3 , Caspasas/metabolismo , Células Cultivadas , Ciclooxigenasa 2/metabolismo , Citocinas/metabolismo , Doxorrubicina , Recuento de Eritrocitos , Eritropoyetina/sangre , Factor de Transcripción GATA4/metabolismo , Insuficiencia Cardíaca/inducido químicamente , Etiquetado Corte-Fin in Situ , Ratones , Ratones Endogámicos C57BL , Miocardio/metabolismo , Miocitos Cardíacos/citología , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Receptores de Eritropoyetina/metabolismo , Sarcómeros/metabolismo , Tasa de Supervivencia , Disfunción Ventricular Izquierda/inducido químicamente , Disfunción Ventricular Izquierda/tratamiento farmacológico , Disfunción Ventricular Izquierda/prevención & controlRESUMEN
BACKGROUND: In patients with end-stage renal disease, angiotensin II type 1A receptor (AT1) blockade attenuates the associated cardiac dysfunction. We investigated the molecular signaling mediating that effect. METHODS AND RESULTS: We used 5/6 nephrectomy to induce significant renal dysfunction in AT1 knockout (AT1KO) and wild-type mice (WT). Twelve weeks after nephrectomy, WT showed significant left ventricular dilation and dysfunction that were accompanied by cardiomyocyte hypertrophy, fibrosis, and reduced capillary density. All of these effects were significantly mitigated in AT1KO. Nephrectomy led to upregulation of myocardial expression of AT1, transforming growth factor-beta1 (TGF-beta1), matrix metalloproteinase (MMP)-2, MMP-9, tissue inhibitor of metalloproteinase-1 (TIMP-1), and phosphorylated Akt (p-Akt), and also led to increased oxidative damage in cardiomyocytes. In AT1KO, TGF-beta1, TIMP-1, oxidative damage levels were lower, whereas MMPs and p-Akt levels were higher. Treating nephrectomized WT mice with valsartan (an AT1 blocker), but not hydralazine, improved cardiac function and altered molecular signaling in a manner similar to that seen in AT1KO mice. Notably, AT1 expression was downregulated in valsartan-treated but not hydralazine-treated hearts. CONCLUSIONS: These findings provide novel insight into the mechanism underlying the beneficial effects of AT1 blockade on cardiac function in a model of renal dysfunction-associated heart failure.
Asunto(s)
Bloqueadores del Receptor Tipo 1 de Angiotensina II/uso terapéutico , Antihipertensivos/uso terapéutico , Insuficiencia Cardíaca/etiología , Fallo Renal Crónico/prevención & control , Receptor de Angiotensina Tipo 1/sangre , Transducción de Señal/fisiología , Tetrazoles/uso terapéutico , Valina/análogos & derivados , Animales , Nitrógeno de la Urea Sanguínea , Western Blotting , Creatinina/sangre , ADN/genética , Modelos Animales de Enfermedad , Insuficiencia Cardíaca/tratamiento farmacológico , Insuficiencia Cardíaca/fisiopatología , Inmunohistoquímica , Fallo Renal Crónico/complicaciones , Fallo Renal Crónico/metabolismo , Masculino , Metaloproteinasa 2 de la Matriz/biosíntesis , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/biosíntesis , Metaloproteinasa 9 de la Matriz/genética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Miocardio/metabolismo , Miocardio/patología , Nefrectomía/efectos adversos , Estrés Oxidativo/genética , Receptor de Angiotensina Tipo 1/efectos de los fármacos , Receptor de Angiotensina Tipo 1/genética , Inhibidor Tisular de Metaloproteinasa-1/genética , Inhibidor Tisular de Metaloproteinasa-1/metabolismo , Factor de Crecimiento Transformador beta1/biosíntesis , Factor de Crecimiento Transformador beta1/genética , Resultado del Tratamiento , Regulación hacia Arriba/efectos de los fármacos , Valina/uso terapéutico , Valsartán , Función Ventricular Izquierda/efectos de los fármacosRESUMEN
BACKGROUND: Fibrosis and progressive failure are prominent pathophysiological features of hearts after myocardial infarction (MI). We examined the effects of inhibiting transforming growth factor-beta (TGF-beta) signaling on post-MI cardiac fibrosis and ventricular remodeling and function. METHODS AND RESULTS: MI was induced in mice by left coronary artery ligation. An adenovirus harboring soluble TGF-beta type II receptor (Ad.CAG-sTbetaRII), a competitive inhibitor of TGF-beta, was then injected into the hindlimb muscles on day 3 after MI (control, Ad.CAG-LacZ). Post-MI survival was significantly improved among sTbetaRII-treated mice (96% versus control at 71%), which also showed a significant attenuation of ventricular dilatation and improved function 4 weeks after MI. At the same time, histological analysis showed reduced fibrous tissue formation. Although MI size did not differ in the 2 groups, MI thickness was greater and circumference was smaller in the sTbetaRII-treated group; within the infarcted area, alpha-smooth muscle actin-positive cells were abundant, which might have contributed to infarct contraction. Apoptosis among myofibroblasts in granulation tissue during the subacute stage (10 days after MI) was less frequent in the sTbetaRII-treated group, and sTbetaRII directly inhibited Fas-induced apoptosis in cultured myofibroblasts. Finally, treatment of MI-bearing mice with sTbetaRII was ineffective if started during the chronic stage (4 weeks after MI). CONCLUSIONS: Postinfarction gene therapy aimed at suppressing TGF-beta signaling mitigates cardiac remodeling by affecting cardiac fibrosis and infarct tissue dynamics (apoptosis inhibition and infarct contraction). This suggests that such therapy may represent a new approach to the treatment of post-MI heart failure, applicable during the subacute stage.
Asunto(s)
Terapia Genética , Insuficiencia Cardíaca/prevención & control , Infarto del Miocardio/terapia , Receptores de Factores de Crecimiento Transformadores beta/administración & dosificación , Factor de Crecimiento Transformador beta/antagonistas & inhibidores , Remodelación Ventricular/efectos de los fármacos , Animales , Apoptosis , Unión Competitiva , Modelos Animales de Enfermedad , Fibrosis/prevención & control , Fibrosis/terapia , Vectores Genéticos/uso terapéutico , Insuficiencia Cardíaca/terapia , Masculino , Ratones , Ratones Endogámicos C57BL , Infarto del Miocardio/patología , Farmacocinética , Proteínas Serina-Treonina Quinasas , Receptor Tipo II de Factor de Crecimiento Transformador beta , Receptores de Factores de Crecimiento Transformadores beta/antagonistas & inhibidores , Receptores de Factores de Crecimiento Transformadores beta/genética , Transducción de Señal/efectos de los fármacos , Tasa de SupervivenciaRESUMEN
In myocardial infarction (MI), granulation tissue cells disappear via apoptosis to complete a final scarring with scanty cells. Blockade of this apoptosis was reported to improve post-MI ventricular remodeling and heart failure. However, the molecular biological mechanisms for the apoptosis are unknown. Fas and Fas ligand were overexpressed in the granulation tissue at the subacute stage of MI (1 week after MI) in mice, where apoptosis frequently occurred. In mice lacking functioning Fas (lpr strain) and in those lacking Fas ligand (gld strain), apoptotic rate of granulation tissue cells was significantly fewer compared with that of genetically controlled mice, and post-MI ventricular remodeling and dysfunction were greatly attenuated. Mice were transfected with adenovirus encoding soluble Fas (sFas), a competitive inhibitor of Fas ligand, on the third day of MI. The treatment resulted in suppression of granulation tissue cell apoptosis and produced a thick, cell-rich infarct scar containing rich vessels and bundles of smooth muscle cells with a contractile phenotype at the chronic stage (4 weeks after MI). This accompanied not only alleviation of heart failure but also survival improvement. However, the sFas gene delivery during scar tissue phase was ineffective, suggesting that beneficial effects of the sFas gene therapy owes to inhibition of granulation tissue cell apoptosis. The Fas/Fas ligand interaction plays a critical role for granulation tissue cell apoptosis after MI. Blockade of this apoptosis by interfering with the Fas/Fas ligand interaction may become one of the therapeutic strategies against chronic heart failure after large MI.
Asunto(s)
Apoptosis/fisiología , Tejido de Granulación/patología , Insuficiencia Cardíaca/fisiopatología , Glicoproteínas de Membrana/fisiología , Infarto del Miocardio/fisiopatología , Miocardio/patología , Remodelación Ventricular/fisiología , Receptor fas/fisiología , Adenoviridae/genética , Animales , Caspasas/análisis , Cicatriz/patología , Vasos Coronarios , Virus Defectuosos/genética , Proteína Ligando Fas , Genes Sintéticos , Terapia Genética , Vectores Genéticos/uso terapéutico , Insuficiencia Cardíaca/etiología , Insuficiencia Cardíaca/prevención & control , Humanos , Hipertrofia Ventricular Izquierda/etiología , Hipertrofia Ventricular Izquierda/fisiopatología , Hipertrofia Ventricular Izquierda/prevención & control , Inmunoglobulina G/genética , Ligadura , Masculino , Glicoproteínas de Membrana/deficiencia , Glicoproteínas de Membrana/genética , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes , Infarto del Miocardio/complicaciones , Infarto del Miocardio/terapia , Solubilidad , Factores de Tiempo , Receptor fas/genética , Receptor fas/uso terapéuticoRESUMEN
BACKGROUND: Effect of hepatocyte growth factor (HGF) has scarcely been determined on diabetic nephropathy. METHODS: Adenovirus encoding human HGF gene or LacZ gene (as the control) was injected into the hindlimb muscles of the C57BL/KsJ-db/db (db/db) mice at the age of 12 weeks, a model of genetic diabetes. Diabetic nephropathy was then evaluated at the age of 24 weeks. RESULTS: The urine volume and albumin excretion progressively decreased in the control, whereas they remained unchanged in the HGF-treated group during the 12-week follow-up. The HGF gene therapy did not affect glucose metabolism. However, it resulted in a better renal function as evaluated by creatinine clearance (Ccr) than the control; Ccr was progressively worsened in controls (0.14 +/- 0.02 liters/day) whereas unchanged in the HGF gene-treated group (0.38 +/- 0.09 liters/day, p < 0.05). Kidneys of the HGF gene-treated mice showed glomeruli with greater area and cell population, smaller glomerular sclerotic index, and less fibrosis in both glomeruli and renal tubules, where apoptotic rate of glomerular endothelial cells and that of tubular epithelial cells were significantly decreased. TGF-beta1 expression was significantly decreased in kidneys of the HGF gene-treated group. Finally, the HGF treatment significantly improved the long-term survival of db/db mice. CONCLUSIONS: The HGF gene delivery thus appeared to slow down the aggravation of diabetic nephropathy in db/db mice by attenuating progression from the hyperfiltration phase into the sclerotic phase through antiapoptotic and antifibrotic actions. The present findings suggest that the HGF gene delivery can be a novel therapeutic approach against diabetic nephropathy.
Asunto(s)
Nefropatías Diabéticas/genética , Nefropatías Diabéticas/terapia , Modelos Animales de Enfermedad , Terapia Genética/métodos , Factor de Crecimiento de Hepatocito/genética , Factor de Crecimiento de Hepatocito/uso terapéutico , Transfección/métodos , Adenoviridae/genética , Animales , ADN Viral/administración & dosificación , Nefropatías Diabéticas/diagnóstico , Progresión de la Enfermedad , Femenino , Vectores Genéticos/genética , Humanos , Pruebas de Función Renal , Ratones , Ratones Endogámicos C57BL , Proteínas Recombinantes/genética , Proteínas Recombinantes/uso terapéutico , Índice de Severidad de la Enfermedad , Resultado del TratamientoAsunto(s)
Adventicia/anomalías , Aterectomía Coronaria/efectos adversos , Vasos Coronarios/diagnóstico por imagen , Adventicia/diagnóstico por imagen , Adventicia/fisiopatología , Anciano , Aterectomía Coronaria/métodos , Angiografía Coronaria/métodos , Vasos Coronarios/fisiopatología , Humanos , Masculino , Persona de Mediana EdadRESUMEN
BACKGROUND: Hepatocyte growth factor (HGF) is implicated in tissue regeneration, angiogenesis, and antiapoptosis. However, its chronic effects are undetermined on postinfarction left ventricular (LV) remodeling and heart failure. METHODS AND RESULTS: In mice, on day 3 after myocardial infarction (MI), adenovirus encoding human HGF (Ad.CAG-HGF) was injected into the hindlimb muscles (n=13). As a control (n=15), LacZ gene was used. A persistent increase in plasma human HGF was confirmed in the treated mice: 1.0+/-0.2 ng/mL 4 weeks later. At 4 weeks after MI, the HGF-treated mice showed improved LV remodeling and dysfunction compared with controls, as indicated by the smaller LV cavity and heart/body weight ratio, greater % fractional shortening and LV +/-dP/dt, and lower LV end-diastolic pressure. The cardiomyocytes near MI, including the papillary muscles and trabeculae, were greatly hypertrophied in the treated mice. The old infarct size was similar between the groups, but the infarct wall was thicker in the treated mice, where the density of noncardiomyocyte cells, including vessels, was greater. Fibrosis of the ventricular wall was significantly reduced in them. Examination of 10-day-old MI revealed no proliferation or apoptosis but showed augmented expression of c-Met/HGF receptor in cardiomyocytes near MI, whereas a greater proliferating activity and smaller apoptotic rate of granulation tissue cells in the HGF-treated hearts was observed compared with controls. CONCLUSIONS: Postinfarction HGF gene therapy improved LV remodeling and dysfunction through hypertrophy of cardiomyocytes, infarct wall thickening, preservation of vessels, and antifibrosis. These findings imply a novel therapeutic approach against postinfarction heart failure.
Asunto(s)
Adenoviridae , Vectores Genéticos/uso terapéutico , Factor de Crecimiento de Hepatocito/biosíntesis , Infarto del Miocardio/fisiopatología , Infarto del Miocardio/terapia , Adenoviridae/genética , Animales , Bromodesoxiuridina , División Celular/efectos de los fármacos , Enfermedad Crónica , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Vectores Genéticos/genética , Factor de Crecimiento de Hepatocito/genética , Factor de Crecimiento de Hepatocito/farmacología , Hepatocitos/efectos de los fármacos , Humanos , Inmunohistoquímica , Masculino , Ratones , Ratones Endogámicos C57BL , Infarto del Miocardio/patología , Miocardio/patología , Tasa de Supervivencia , Factores de Tiempo , Transducción Genética/métodos , Resultado del Tratamiento , Disfunción Ventricular Izquierda/tratamiento farmacológico , Disfunción Ventricular Izquierda/genética , Remodelación Ventricular/efectos de los fármacos , Remodelación Ventricular/genéticaRESUMEN
OBJECTIVES: We hypothesized that erythropoietin (EPO)-immersed gelatin hydrogel microspheres (GHM) injected into ischemic legs might continuously release a small amount of EPO to locally stimulate angiogenesis without unfavorable systemic effects. BACKGROUND: EPO is a potent angiogenic factor, but its use for relieving ischemic organs is limited because of the untoward systemic erythrogenic effect and its short half-life in plasma. METHODS: The right femoral arteries of BALB/c mice were ligated. Recombinant human EPO (5,000 IU/kg)-immersed GHM was injected into the right hind limb muscles (n = 12); the control groups included a saline-injected group (n = 12), an EPO-injected group (n = 8), and an empty GHM-injected group (n = 8). RESULTS: Eight weeks later, improvement of blood perfusion to the ischemic limb was significantly augmented in the EPO-GHM group compared with any of the control groups. There was no increase in the hemoglobin level, nor was there any increase in endothelial progenitor cells. However, capillary and arteriolar densities were significantly increased in this group. Although the treatment did not affect the levels of vascular endothelial growth factor or interleukin-1 beta, it up-regulated the EPO receptor and matrix metalloproteinase-2 and activated the downstream signaling of Akt and also endothelial nitric oxide synthase in ischemic limbs, which might have been associated with the evident angiogenic and arteriogenic effects in the present system. CONCLUSIONS: The present drug delivery system is suggested to have potential as a novel noninvasive therapy for ischemic peripheral artery disease.
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Eritropoyetina/administración & dosificación , Isquemia/tratamiento farmacológico , Extremidad Inferior/irrigación sanguínea , Enfermedades Vasculares Periféricas/tratamiento farmacológico , Células Madre Adultas/efectos de los fármacos , Inductores de la Angiogénesis/metabolismo , Animales , Células Cultivadas , Preparaciones de Acción Retardada , Células Endoteliales/efectos de los fármacos , Hidrogeles/uso terapéutico , Isquemia/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C , Microesferas , Miocitos del Músculo Liso/efectos de los fármacos , Neovascularización Fisiológica/efectos de los fármacos , Enfermedades Vasculares Periféricas/metabolismo , Receptores de Eritropoyetina/metabolismo , Proteínas Recombinantes , Flujo Sanguíneo Regional/efectos de los fármacosRESUMEN
We hypothesized that therapy, composed of antiapoptotic soluble Fas (sFas) gene transfer, combined with administration of the cardioprotective cytokine granulocyte colony-stimulating factor (G-CSF), would markedly mitigate cardiac remodeling and dysfunction following myocardial infarction (MI). On the 3rd day after MI induced by ligating the left coronary artery in mice, four different treatments were initiated: saline injection (Group C, n = 26); G-CSF administration (Group G, n = 27); adenoviral transfer of sFas gene (Group F, n = 26); and the latter two together (Group G+F, n = 26). Four weeks post-MI, Group G+F showed better survival than Group C (96 vs. 65%, P < 0.05) and the best cardiac function among the four groups. In Group G, the infarct scar was smaller and less fibrotic, whereas in Group F the scar was thicker, without a reduction in area, and contained abundant myofibroblasts and vascular cells; Group G+F showed both phenotypes. G-CSF exerted a beneficial effect on infarct tissue dynamics through antifibrotic and proliferative effects on granulation tissue; however, it also exerts an adverse proapoptotic effect that leads to thinning of the infarct scar. sFas appeared to offset the latter drawback. In vitro study using cultured myofibroblasts derived from the infarct tissue revealed that G-CSF increased proliferating activity of those cells accompanying activation of Akt and signal transducer and activator of transcription 3, while accelerating Fas-mediated apoptosis with increasing Bax-to-Bcl-2 ratio. The results suggest that combined use of G-CSF administration and sFas gene therapy is a potentially powerful tool against post-MI heart failure.
Asunto(s)
Apoptosis , Cardiotónicos/farmacología , Técnicas de Transferencia de Gen , Terapia Genética , Factor Estimulante de Colonias de Granulocitos/farmacología , Insuficiencia Cardíaca/terapia , Infarto del Miocardio/terapia , Miocardio/patología , Receptor fas/genética , Adenoviridae/genética , Animales , Apoptosis/efectos de los fármacos , Apoptosis/genética , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Terapia Combinada , Modelos Animales de Enfermedad , Fibroblastos/efectos de los fármacos , Fibroblastos/patología , Fibrosis , Vectores Genéticos , Tejido de Granulación/efectos de los fármacos , Tejido de Granulación/patología , Insuficiencia Cardíaca/etiología , Insuficiencia Cardíaca/genética , Insuficiencia Cardíaca/patología , Insuficiencia Cardíaca/fisiopatología , Humanos , Lenograstim , Masculino , Ratones , Ratones Endogámicos C57BL , Contracción Miocárdica/efectos de los fármacos , Infarto del Miocardio/complicaciones , Infarto del Miocardio/genética , Infarto del Miocardio/patología , Infarto del Miocardio/fisiopatología , Miocardio/metabolismo , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteínas Recombinantes/farmacología , Regeneración/efectos de los fármacos , Regeneración/genética , Factores de Tiempo , Disfunción Ventricular Izquierda/etiología , Disfunción Ventricular Izquierda/genética , Disfunción Ventricular Izquierda/patología , Disfunción Ventricular Izquierda/terapia , Remodelación Ventricular/efectos de los fármacos , Proteína X Asociada a bcl-2/metabolismo , Receptor fas/metabolismoRESUMEN
Hepatocyte growth factor (HGF) reportedly exerts beneficial effects on the heart following myocardial infarction and during nonischemic cardiomyopathy, but the precise mechanisms underlying the latter have not been well elucidated. We generated nonischemic cardiomyopathy in mice by injecting them with doxorubicin (15 mg/kg ip). Two weeks later, when cardiac dysfunction was apparent, an adenoviral vector encoding human HGF gene (Ad.CAG-HGF, 1x10(11) particles/mouse) was injected into the hindlimb muscles; LacZ gene served as the control. Left ventricular dilatation and dysfunction normally seen 4 wk after doxorubicin administration were significantly mitigated in HGF-treated mice, as were the associated cardiomyocyte atrophy/degeneration and myocardial fibrosis. Myocardial expression of GATA-4 and a sarcomeric protein, myosin heavy chain, was downregulated by doxorubicin, but the expression of both was restored by HGF treatment. The protective effect of HGF against doxorubicin-induced cardiomyocyte atrophy was confirmed in an in vitro experiment, which also showed that neither cardiomyocyte apoptosis nor proliferation plays significant roles in the present model. Upregulation of c-Met/HGF receptor was noted in HGF-treated hearts. Among the mediators downstream of c-Met, the activation of extracellular signal-regulated kinase (ERK) was reduced by doxorubicin, but the activity was restored by HGF. Levels of transforming growth factor-beta1 and cyclooxygenase-2 did not differ between the groups. Our findings suggest the HGF gene delivery exerts therapeutic antiatrophic/degenerative and antifibrotic effects on myocardium in cases of established cardiac dysfunction caused by doxorubicin. These beneficial effects appear to be related to HGF-induced ERK activation and upregulation of c-Met, GATA-4, and sarcomeric proteins.
Asunto(s)
Adenoviridae/genética , Antibióticos Antineoplásicos , Cardiomiopatías/inducido químicamente , Cardiomiopatías/genética , Doxorrubicina , Factor de Crecimiento de Hepatocito/genética , Factor de Crecimiento de Hepatocito/fisiología , Animales , Animales Recién Nacidos , Western Blotting , Cardiomiopatías/fisiopatología , Ciclooxigenasa 2/metabolismo , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Factor de Transcripción GATA4/genética , Factor de Transcripción GATA4/fisiología , Vectores Genéticos , Corazón/fisiología , Humanos , Inmunohistoquímica , Inmunoprecipitación , Etiquetado Corte-Fin in Situ , Ratones , Ratones Endogámicos C57BL , Microscopía Electrónica , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/fisiología , Plásmidos/genética , Proteínas Proto-Oncogénicas c-met/metabolismoRESUMEN
Although beneficial effects of granulocyte colony-stimulating factor (G-CSF) have been demonstrated on post-myocardia infarction (MI) process, the mechanisms and feasibility are not fully agreed yet. We investigated effects of a long-term treatment with a low-dose G-CSF started 1 day after the onset of MI, on post-infarction process. One day after being made MI by left coronary ligation, mice were given G-CSF (10 microg/kg/day) for 4 weeks. The G-CSF treatment resulted in a significant mitigation of cardiac remodelling and dysfunction. In the G-CSF-treated hearts, the infarcted scar was smaller with less fibrosis and abundant vessels while in the non-infarcted area, hypertrophic cardiomyocytes with attenuated degenerative changes and reduced fibrosis were apparent. These effects were accompanied by activation of signal transducer and activator of transcription 3 (STAT3) and Akt and also by up-regulation of GATA-4, myosin heavy chain and matrix metalloproteinases-2 and -9. Apoptosis of cardiomyocytes appeared insignificant at any stages. Parthenolide, a STAT3 inhibitor, completely abolished the beneficial effects of G-CSF on cardiac function and remodelling with loss of effect on both anti-cardiomyocyte degeneration and anti-fibrosis. In contrast, wortmannin, an Akt inhibitor, did not affect G-CSF-induced benefits despite cancelling vessel increase. In conclusion, treatment with G-CSF at a small dose but for a long duration beneficially affects the post-infarction process possibly through STAT3-mediated anti-cardiomyocyte degeneration and anti-fibrosis, but not through anti-cardiomyocyte apoptosis or Akt-mediated angio-genesis. The findings may also imply a more feasible way of G-CSF administration in the clinical settings.
Asunto(s)
Factor Estimulante de Colonias de Granulocitos/administración & dosificación , Factor Estimulante de Colonias de Granulocitos/uso terapéutico , Infarto del Miocardio/tratamiento farmacológico , Miocardio/patología , Animales , Apoptosis/efectos de los fármacos , Recuento de Células Sanguíneas , Supervivencia Celular/efectos de los fármacos , Factor Estimulante de Colonias de Granulocitos/farmacología , Granulocitos/citología , Granulocitos/efectos de los fármacos , Pruebas de Función Cardíaca , Humanos , Quinasas Janus/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Infarto del Miocardio/enzimología , Infarto del Miocardio/fisiopatología , Miocardio/enzimología , Miocardio/ultraestructura , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/enzimología , Miocitos Cardíacos/patología , Miocitos Cardíacos/ultraestructura , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Receptores de Factor Estimulante de Colonias de Granulocito/metabolismo , Proteínas Recombinantes , Factores de Transcripción STAT/metabolismo , Transducción de Señal/efectos de los fármacos , Factores de TiempoRESUMEN
Although amlodipine, a long-acting L-type calcium channel blocker, reportedly prevents left ventricular remodeling and dysfunction after myocardial infarction, the mechanism responsible is not yet well understood. Myocardial infarction was induced in mice by ligating the left coronary artery. Treatment of mice with amlodipine (10 mg x kg(-1) x day(-1)), beginning on the third day postinfarction, significantly improved survival and attenuated left ventricular dilatation and dysfunction 4 wk postinfarction compared with treatment with saline or hydralazine. Although infarct sizes did not differ among the groups, the infarcted wall thickness was greater and the infarct segment length was smaller in the amlodipine-treated group, and cellular components, including vessels and myofibroblasts, were abundant within the infarcted area. Ten days postinfarction (the subacute stage), the proliferation of granulation tissue cells in the infarcted area was similar among the groups, but the incidence of apoptosis was significantly lower in the amlodipine-treated group, where Bad, a proapoptotic Bcl-2 family protein, was significantly phosphorylated (inactivated). Calcineurin, which dephosphorylates (activates) Bad, was upregulated in infarcted hearts, but its levels were significantly reduced by amlodipine treatment. In vitro, Fas stimulation augmented calcineurin activity and induced apoptosis among infarct tissue-derived myofibroblasts; both of those effects were strongly inhibited by amlodipine, two other calcium channel blockers (verapamil or nifedipine), and two calcineurin inhibitors (cyclosporin A or FK-506). Amlodipine inhibits Fas-mediated granulation tissue cell apoptosis in infarcted hearts, possibly by attenuating the activities of calcineurin and Bad. These findings may provide new insight into the mechanism by which calcium channel blockers attenuate postinfarction cardiac remodeling and dysfunction.
Asunto(s)
Amlodipino/farmacología , Apoptosis/efectos de los fármacos , Calcineurina/metabolismo , Bloqueadores de los Canales de Calcio/farmacología , Tejido de Granulación/efectos de los fármacos , Infarto del Miocardio/tratamiento farmacológico , Disfunción Ventricular Izquierda/prevención & control , Remodelación Ventricular/efectos de los fármacos , Amlodipino/uso terapéutico , Animales , Inhibidores de la Calcineurina , Calcio/metabolismo , Bloqueadores de los Canales de Calcio/uso terapéutico , Canales de Calcio/metabolismo , Células Cultivadas , Vasos Coronarios/cirugía , Ciclosporina/farmacología , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/farmacología , Tejido de Granulación/metabolismo , Tejido de Granulación/patología , Tejido de Granulación/fisiopatología , Hidralazina/farmacología , Ligadura , Masculino , Ratones , Ratones Endogámicos C57BL , Infarto del Miocardio/complicaciones , Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología , Infarto del Miocardio/fisiopatología , Fosforilación , Proyectos de Investigación , Tacrolimus/farmacología , Factores de Tiempo , Vasodilatadores/farmacología , Disfunción Ventricular Izquierda/etiología , Disfunción Ventricular Izquierda/metabolismo , Disfunción Ventricular Izquierda/patología , Disfunción Ventricular Izquierda/fisiopatología , Función Ventricular Izquierda/efectos de los fármacos , Proteína Letal Asociada a bcl/metabolismo , Receptor fas/metabolismoRESUMEN
It is not well-known yet how granulocyte colony-stimulating factor (G-CSF) affects nonischemic cardiomyopathy, though its beneficial effects on acute myocardial infarction are well-established. We hypothesize that G-CSF beneficially might affect nonischemic cardiomyopathy through the direct cardioprotective effects. Here, we show that a single injection of doxorubicin (DOX, 15 mg/kg) induced left ventricular dilatation and dysfunction in mice within 2 weeks, and that these effects were significantly attenuated by human recombinant G-CSF (100 microg/kg/day for 5 days). G-CSF also protected hearts against DOX-induced cardiomyocyte atrophy/degeneration, fibrosis, inflammatory cell infiltration and down regulation of GATA-4 and sarcomeric proteins, myosin heavy chain, troponin I and desmin, both in vivo and in vitro. Cardiac cyclooxygenase-2 was upregulated and G-CSF receptor was downregulated in DOX-induced cardiomyopathy, but both of those effects were largely reversed by G-CSF. No DOX-induced apoptotic effects were seen, nor were there any changes in tumor necrosis factor-alpha or transforming growth factor-beta1 levels. Among downstream mediators of G-CSF receptor signaling, DOX-induced cardiomyopathy involved inactivation of extracellular signal-regulated protein kinase (ERK); the ERK inactivation was reversed by G-CSF. Inhibition of ERK activation, but not cyclooxygenase-2 inhibition, completely abolished beneficial effect of G-CSF on cardiac function. G-CSF did not promote differentiation of bone marrow cells into cardiomyocytes according to the experiment using green fluorescent protein-chimeric mice, and inhibition of CXCR4+ cell homing using AMD3100 did not diminish the effect of G-CSF. Finally, G-CSF was also effective when administered after cardiomyopathy was established. In conclusion, these findings imply the therapeutic usefulness of G-CSF mainly through restoring ERK activation against DOX-induced nonischemic cardiomyopathy.