RESUMO
AIMS: Recent studies revealed that the bromodomain and extra-terminal (BET) epigenetic reader proteins resemble key regulators in the underlying pathophysiology of cancer, diabetes, or cardiovascular disease. However, whether they also regulate vascular remodelling processes by direct effects on vascular cells is unknown. In this study, we investigated the effects of the BET proteins on human smooth muscle cell (SMC) function in vitro and neointima formation in response to vascular injury in vivo. METHODS AND RESULTS: Selective inhibition of BETs by the small molecule (+)-JQ1 dose-dependently reduced proliferation and migration of SMCs without apoptotic or toxic effects. Flow cytometric analysis revealed a cell cycle arrest in the G0/G1 phase in the presence of (+)-JQ1. Microarray- and pathway analyses revealed a substantial transcriptional regulation of gene sets controlled by the Forkhead box O (FOXO1)1-transcription factor. Silencing of the most significantly regulated FOXO1-dependent gene, CDKN1A, abolished the antiproliferative effects. Immunohistochemical colocalization, co-immunoprecipitation, and promoter-binding ELISA assay data confirmed that the BET protein BRD4 directly binds to FOXO1 and regulates FOXO1 transactivational capacity. In vivo, local application of (+)-JQ1 significantly attenuated SMC proliferation and neointimal lesion formation following wire-induced injury of the femoral artery in C57BL/6 mice. CONCLUSION: Inhibition of the BET-containing protein BRD4 after vascular injury by (+)-JQ1 restores FOXO1 transactivational activity, subsequent CDKN1A expression, cell cycle arrest and thus prevents SMC proliferation in vitro and neointima formation in vivo. Inhibition of BET epigenetic reader proteins might thus represent a promising therapeutic strategy to prevent adverse vascular remodelling.
Assuntos
Lesões das Artérias Carótidas/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proliferação de Células , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Neointima , Proteínas Nucleares/metabolismo , Proteínas/metabolismo , Fatores de Transcrição/metabolismo , Lesões do Sistema Vascular/metabolismo , Animais , Azepinas/farmacologia , Lesões das Artérias Carótidas/genética , Lesões das Artérias Carótidas/patologia , Pontos de Checagem do Ciclo Celular , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ciclo Celular/genética , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Vasos Coronários/efeitos dos fármacos , Vasos Coronários/metabolismo , Vasos Coronários/patologia , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Modelos Animais de Doenças , Proteína Forkhead Box O1/genética , Proteína Forkhead Box O1/metabolismo , Compostos Heterocíclicos de 4 ou mais Anéis/metabolismo , Humanos , Masculino , Camundongos Endogâmicos C57BL , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/lesões , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/patologia , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/genética , Proteínas/antagonistas & inibidores , Proteínas/genética , Transdução de Sinais , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/genética , Triazóis/farmacologia , Lesões do Sistema Vascular/genética , Lesões do Sistema Vascular/patologiaRESUMO
BACKGROUND: The novel nonsteroidal mineralocorticoid receptor (MR) antagonist finerenone holds promise to be safe and efficient in the treatment of patients with heart failure and/or chronic kidney disease. However, its effects on vascular function remain elusive. PURPOSE: The aim of this study was to determine the functional effect of selective MR antagonism by finerenone in vascular cells in vitro and the effect on vascular remodeling following acute vascular injury in vivo. METHODS AND RESULTS: In vitro, finerenone dose-dependently reduced aldosterone-induced smooth muscle cell (SMC) proliferation, as quantified by BrdU incorporation, and prevented aldosterone-induced endothelial cell (EC) apoptosis, as measured with a flow cytometry based caspase 3/7 activity assay. In vivo, oral application of finerenone resulted in an accelerated re-endothelialization 3 days following electric injury of the murine carotid artery. Furthermore, finerenone treatment inhibited intimal and medial cell proliferation following wire-induced injury of the murine femoral artery 10 days following injury and attenuated neointimal lesion formation 21 days following injury. CONCLUSION: Finerenone significantly reduces apoptosis of ECs and simultaneously attenuates SMC proliferation, resulting in accelerated endothelial healing and reduced neointima formation of the injured vessels. Thus, finerenone appears to provide favorable vascular effects through restoring vascular integrity and preventing adverse vascular remodeling.