RESUMO
Chronic kidney disease (CKD) is an increasingly common condition characterized by progressive loss of functional nephrons leading to renal failure. TGF-ß1-induced mesangial cell (MC) phenotype alterations have been linked to the genesis of CKD. Here we show that TGF-ß1 regulates TBX3 gene expression in MC. This gene encodes for two main isoforms, TBX3.1 and TBX3+2α. TBX3.1 has been implicated in cell immortalization, proliferation and apoptosis by inhibiting p14(ARF)-Mdm2-p53 pathway, while TBX3+2α role has not been defined. We demonstrated that TBX3 overexpression abrogated MC apoptosis induced by serum deprivation. Moreover, we observed an enhancement in TBX3 protein expression both in glomerular and tubular regions in the model of 5/6 nephrectomy, temporally related to increased expression of TGF-ß1, type IV collagen and fibronectin. Our results indicate that TBX3 acts as an anti-apoptotic factor in MC in vitro and may be involved in the mechanism by which TGF-ß1 induces glomerulosclerosis and tubular fibrosis during the progression of nephropathies.
Assuntos
Apoptose/genética , Células Mesangiais/metabolismo , Proteínas com Domínio T/genética , Proteínas com Domínio T/metabolismo , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismo , Proliferação de Células/genética , Células Cultivadas , Colágeno Tipo IV/genética , Colágeno Tipo IV/metabolismo , Fibronectinas/genética , Fibronectinas/metabolismo , Fibrose/genética , Fibrose/metabolismo , Fibrose/patologia , Expressão Gênica/genética , Humanos , Células Mesangiais/patologia , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismoRESUMO
BACKGROUND: Patients with coronary artery disease (CAD) should be treated with statins to attain very low cholesterol levels, in order to reduce cardiovascular adverse events. More than 70% of these patients do not reach the appropriate cholesterol goal despite moderate statin doses. However, it is not known whether therapeutic uptitration with different lipid-lowering strategies has a similar "pleiotropic" effect on atherosclerotic endothelial dysfunction evaluated by measurement of endothelial progenitor cells (EPCs). OBJECTIVE: We sought to compare, in patients with stable CAD and with a low-density lipoprotein cholesterol (LDL-C) >70 mg/dL on treatment with simvastatin 20 mg, the effects on EPCs by increasing simvastatin to 80 mg versus adding ezetimibe 10 mg. METHODS: Patients (n = 68, 63 ± 9 years, 39% men) were randomly allocated to receive ezetimibe 10/simvastatin 20 mg or simvastatin 80 mg for 6 weeks. Circulating EPCs were measured by flow cytometry before and after the treatment. RESULTS: Both strategies presented similar effects on metabolic parameters. The LDLs were equally reduced by ezetimibe 10/simvastatin 20 mg and simvastatin 80 mg (28.9% ± 13% vs 21.1% ± 33%; P = .46, respectively). The levels of EPCs were unaffected by ezetimibe 10/simvastatin 20 mg (median [25th, 75th]: pre- vs posttreatment, 7.0 [2.3; 13.3] vs 3.1 [0.1; 13.2] EPCs/10(4) mononuclear cells; P = .43) or simvastatin 80 mg (pre- vs posttreatment, 6.1 [2.9; 15.2] vs 4.0 [1.4; 10.7] EPCs/10(4) mononuclear cells; P = .5), and there were no differences between the groups on treatment effects (P = .9). CONCLUSIONS: Among stable patients with CAD and with an LDL-C >70 mg/dL on simvastatin 20 mg, increasing simvastatin dose to 80 mg or adding ezetimibe 10 mg promoted similar further cholesterol reduction but did not have incremental effects on circulating EPCs. These data suggest that the effects of simvastatin moderate doses on EPCs are not increased by intensive lipid-lowering strategies (clinicaltrials.gov: NCT00474123).
Assuntos
Anticolesterolemiantes/uso terapêutico , Azetidinas/uso terapêutico , Doença da Artéria Coronariana/tratamento farmacológico , Hipercolesterolemia/tratamento farmacológico , Sinvastatina/uso terapêutico , Idoso , Anticolesterolemiantes/administração & dosagem , Anticolesterolemiantes/farmacologia , Azetidinas/administração & dosagem , Azetidinas/farmacologia , LDL-Colesterol/sangue , LDL-Colesterol/efeitos dos fármacos , Doença da Artéria Coronariana/fisiopatologia , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Combinação Ezetimiba e Simvastatina , Feminino , Citometria de Fluxo , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hipercolesterolemia/complicações , Masculino , Pessoa de Meia-Idade , Sinvastatina/administração & dosagem , Sinvastatina/farmacologia , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismoAssuntos
Doença da Artéria Coronariana/tratamento farmacológico , Células Endoteliais , Mediadores da Inflamação/sangue , Ativação Plaquetária/fisiologia , Células-Tronco , Idoso , Aspirina/uso terapêutico , Biomarcadores , Proteína C-Reativa/análise , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inibidores da Agregação Plaquetária/uso terapêutico , Testes de Função Plaquetária , Estatísticas não Paramétricas , Fatores de TempoAssuntos
Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença da Artéria Coronariana/tratamento farmacológico , Células Endoteliais , Mediadores da Inflamação/sangue , Ativação Plaquetária/fisiologia , Células-Tronco , Aspirina/uso terapêutico , Biomarcadores , Proteína C-Reativa/análise , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/patologia , Testes de Função Plaquetária , Inibidores da Agregação Plaquetária/uso terapêutico , Estatísticas não Paramétricas , Fatores de TempoRESUMO
BACKGROUND: In the setting of stable coronary artery disease (CAD), it is not known if the pleiotropic effects of cholesterol reduction differ between combined ezetimibe/simvastatin and high-dose simvastatin alone. OBJECTIVE: We sought to compare the anti-inflammatory and antiplatelet effects of ezetimibe 10mg/simvastatin 20mg (E10/S20) with simvastatin 80 mg (S80). METHODS AND RESULTS: CAD patients (n=83, 63 ± 9 years, 57% men) receiving S20, were randomly allocated to receive E10/S20 or S80, for 6 weeks. Lipids, inflammatory markers (C-reactive protein, interleukin-6, monocyte chemoattractant protein-1, soluble CD40 ligand and oxidized LDL), and platelet aggregation (platelet function analyzer [PFA]-100) changes were determined. Baseline lipids, inflammatory markers and PFA-100 were similar between groups. After treatment, E10/S20 and S80 patients presented, respectively: (1) similar reduction in LDL-C (29 ± 13% vs. 28 ± 30%, p=0.46), apo-B (18 ± 17% vs. 22 ± 15%, p=0.22) and oxidized LDL (15 ± 33% vs. 18 ± 47%, p=0.30); (2) no changes in inflammatory markers; and, (3) a higher increase of the PFA-100 with E10/S20 than with S80 (27 ± 43% vs. 8 ± 33%, p=0.02). CONCLUSIONS: These data suggest that among stable CAD patients treated with S20, (1) both E10/S20 and S80 were equally effective in further reducing LDL-C; (2) neither treatment had any further significant anti-inflammatory effects; and (3) E10/S20 was more effective than S80 in inhibiting platelet aggregation. Thus, despite similar lipid lowering and doses 4× less of simvastatin, E10/S20 induced a greater platelet inhibitory effect than S80.
Assuntos
Anticolesterolemiantes/administração & dosagem , Azetidinas/administração & dosagem , Doença da Artéria Coronariana/tratamento farmacológico , Hipercolesterolemia/tratamento farmacológico , Sinvastatina/administração & dosagem , Idoso , Apolipoproteínas B/sangue , Biomarcadores/sangue , LDL-Colesterol/sangue , Doença da Artéria Coronariana/sangue , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Ezetimiba , Feminino , Humanos , Hipercolesterolemia/sangue , Lipoproteínas LDL/sangue , Masculino , Pessoa de Meia-Idade , Agregação Plaquetária/efeitos dos fármacosRESUMO
The triterpene tormentic acid (TA) has been reported to exhibit anticancer, anti-inflammatory and anti-atherogenic properties, and minimal toxicity has been detected in in vivo. Vascular smooth muscle cell (VSMC) proliferation and apoptosis resistance are hallmarks of vasculoproliferative diseases, such as post-angioplasty restenosis. The present study was designed to assess the effects of TA on the phenotype of cultured VSMC. The exposure of VSMC to TA (30 muM) significantly increased apoptosis of serum-deprived A7r5 cells, whereas cell survival in the presence of 10% fetal bovine serum was less affected by the drug. On the other hand, even in the presence of serum, A7r5 cell proliferation was significantly inhibited by TA, an effect that persisted for at least 8 days of daily administration of TA. As preservation of endothelial integrity is critical to normal vascular function, we also evaluated the effects of TA on human umbilical cord endothelial cells (HUVEC). Interestingly, TA did not produce significant changes in the levels of apoptosis and proliferation of HUVEC. Our data indicate that TA is a VSMC apoptosis inducer and proliferation inhibitor. The anti-growth action in VSMC in the presence of serum, and the absence of significant effects in endothelial cells suggest that TA may control VSMC abnormal proliferation and cell death resistance without affecting the normal vasculature. We conclude that TA should be investigated further as a potential tool for the prevention and treatment of proliferative vascular diseases, particularly in the setting of post-angioplasty restenosis.
Assuntos
Proliferação de Células/efeitos dos fármacos , Músculo Liso Vascular/efeitos dos fármacos , Miócitos de Músculo Liso/efeitos dos fármacos , Triterpenos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Bovinos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Meios de Cultura Livres de Soro , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Endotélio Vascular/citologia , Humanos , Músculo Liso Vascular/citologia , Miócitos de Músculo Liso/citologia , RatosRESUMO
Recent reports highlight the importance of BMP in the vasculature. We investigated the expression pattern and role of the BMP antagonist gremlin in VSMC. We detected gremlin mRNA constitutive expression in adult and embryonic rat aortic VSMC, and in rat carotids. In vitro analysis demonstrated that angiotensin II, TGF-beta1 and PDGF induced significant changes in gremlin mRNA expression. Gremlin stable overexpression in A7r5 cells blocked BMP signaling. BMP-induced reduction in VSMC DNA synthesis was markedly inhibited by gremlin overexpression. In fact, gremlin overexpression increased DNA synthesis and cell counts, and accelerated cell cycle progression of VSMC, through mechanisms that include p27(kip1) down-regulation. Gremlin also led to marked increments in VSMC migration. In addition, gremlin gene silencing promoted a significant blockade on cell proliferation and migration. In vivo studies disclosed increased gremlin protein expression in the neointima of balloon-injured carotid arteries. In summary, the BMP antagonist gremlin is constitutively expressed in the normal vasculature. Gremlin induces VSMC proliferation and migration and is significantly regulated by growth factors and injury. We postulate that gremlin plays a part in the development of pathological phenotypic changes of adult VSMC.
Assuntos
Proteínas Morfogenéticas Ósseas/metabolismo , Movimento Celular , Músculo Liso Vascular/citologia , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/metabolismo , Animais , Proteínas Morfogenéticas Ósseas/farmacologia , Proliferação de Células/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p27/genética , Citocinas , DNA/biossíntese , Regulação para Baixo/efeitos dos fármacos , Inativação Gênica/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Músculo Liso Vascular/efeitos dos fármacos , Miócitos de Músculo Liso/efeitos dos fármacos , Fenótipo , Proteínas , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Túnica Íntima/efeitos dos fármacos , Túnica Íntima/patologiaRESUMO
Rapamycin (RP; rapamune, sirolimus) is a potent inhibitor of vascular smooth muscle cell proliferation and migration. RP was demonstrated to reduce vascular neointimal formation in different animal models of vascular smooth muscle cell proliferation, and clinical use of RP-eluting stents promotes significant reductions in in-stent restenosis rates. However, high costs still preclude the widespread use of these devices. Oral administration of RP associated to bare metal stent delivery has been advocated as an effective and considerably less expensive alternative for restenosis prevention. It is noteworthy that the presence of RP-eluting stents has been associated with reduced endothelial-dependent vasodilation and coronary spasm. In addition, RP has been demonstrated to prevent vasculogenesis. This study evaluated the effects of RP on endothelium-dependent vascular tone and demonstrated that in vitro incubation with high concentrations of RP did not modify either contraction or relaxation of aortic rings. Similar results were obtained after in vivo administration of the drug. These findings suggest that function of adult, non-proliferative rat endothelial cells involved in vascular tone control is not affected by orally administered RP.
Assuntos
Imunossupressores/farmacologia , Músculo Liso Vascular/efeitos dos fármacos , Sirolimo/farmacologia , Animais , Aorta Torácica/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Técnicas In Vitro , Masculino , Tono Muscular/efeitos dos fármacos , Nitroprussiato/farmacologia , Ratos , Ratos Wistar , Vasodilatadores/farmacologiaRESUMO
BACKGROUND: We investigated the effects of amitriptyline in the urinary tract smooth muscle and urolithiasis. METHODS: Cats presenting with obstructive acute renal failure (ARF) received amitriptyline, and renal function and survival rates were analyzed. Isometric contractions and membrane potentials of rat, pig, or human isolated urinary tract smooth muscle were recorded in the presence or absence of amitriptyline. RESULTS: Twenty cats with obstructive ARF caused by urethral plugs received amitriptyline. In all cases, plugs were completely eliminated, and renal function returned to normal, with a 100% survival rate in the follow-up. Amitriptyline produced potent relaxations in rat urethral strips, accompanied by significant reductions in urethral ring membrane potential. This effect was prevented by pretreatment of urethral rings with 4-aminopyridine (4-AP), a voltage-dependent potassium channel blocker. Amitriptyline abolished in a reversible manner acetylcholine-, bradykinin-, and KCl-induced contractions in rat isolated bladder, and this effect was also prevented by 4-AP. Of interest, spontaneous and KCl-induced contractions of pig and human isolated ureter were also blocked by amitriptyline. CONCLUSION: Our results indicate that amitriptyline is an effective and potent relaxant of urinary tract smooth muscle and this effect is mediated by opening of voltage dependent-potassium channels. We suggest that amitriptyline administration may help to promote elimination of urinary calculi.
Assuntos
Amitriptilina/uso terapêutico , Relaxamento Muscular , Músculo Liso/efeitos dos fármacos , Cálculos Urinários/tratamento farmacológico , Sistema Urinário/efeitos dos fármacos , Injúria Renal Aguda/tratamento farmacológico , Animais , Gatos , Humanos , Técnicas In Vitro , Masculino , Músculo Liso/fisiopatologia , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo , Ratos , Ratos Wistar , Suínos , Ureter/efeitos dos fármacos , Ureter/fisiopatologia , Uretra/efeitos dos fármacos , Uretra/fisiopatologia , Bexiga Urinária/efeitos dos fármacos , Bexiga Urinária/fisiopatologia , Sistema Urinário/fisiopatologiaRESUMO
Bradykinin (BK) elicits extracellular-dependent [Ca2+](i) elevations in mouse mesangial cells (MMC) that are not blocked by verapamil, nifedipine, L-nicardipine, NiCl(2), or LaCl(3). The aim of the present study was to evaluate the mechanisms involved in calcium influx induced by BK in MMC. [Ca2+](i) was analyzed through spectrofluorometry employing fura-2-AM, and the data were expressed as [Ca2+](i )obtained/[Ca2+](i )basal ratio. Heparin (IP(3), a receptor antagonist) almost abolished the effects of BK in MMC (1.85 +/- 0.15 vs. 1.13 +/- 0.02, n = 4, p = 0.001). Following external and intracellular calcium store depletion, BK's effect was absent even after successful extracellular calcium replenishment. ML-7 (a myosin light chain kinase inhibitor) blocked responses to thapsigargin (2.62 +/- 0.13 vs. 1.11 +/- 0.04, n = 4, p < 0.001), but not those of BK (6.51 +/- 0.39, n = 6, vs. 5.86 +/- 1.17, n = 4, p = 0.39). On the other hand, genistein (a tyrosine kinase inhibitor) was able to inhibit thapsigargin (3.12 +/- 0.22, n = 5, vs. 1.28 +/- 0.16, n = 4, p < 0.001) as well as BK responses (6.46 +/- 0.66 vs. 2.89 +/- 0.61, n = 4, p < 0.05). Econazole (a P-450 monooxygenase inhibitor) inhibited the responses to both thapsigargin (3.45 +/- 0.16 vs. 1.03 +/- 0.03, n = 4, p < 0.001) and BK (6.49 +/- 0.83, n = 6, vs. 1.17 +/- 0.08, n = 4, p = 0.01). Finally, responses to BK were not affected by indomethacin (6.69 +/- 0.66 vs. 6.57 +/- 0.87, n = 4, p = 0.916). Thus, BK promotes an IP(3)-sensitive store-dependent calcium influx in MMC. This phenomenon seems to involve tyrosine kinase and P-450 monooxygenase products in its transduction pathway.