ABSTRACT
BACKGROUND: Circular RNAs (circRNAs) function as important modulators in the progression of pulmonary arterial hypertension (PAH). Here, we aimed to discover the role and working mechanism of circATP2B4 in hypoxia-induced proliferation and migration of PASMCs. METHODS: The proliferation, migration and apoptosis of pulmonary arterial smooth muscle cells (PASMCs) were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), wound healing assay and flow cytometry. The expression of circATP2B4, ATPase plasma membrane Ca2+ transporting 4 (ATP2B4), microRNA-223 (miR-223) and ATR serine/threonine kinase (ATR) was quantified by quantitative real time polymerase chain reaction (qRT-PCR). Circular RNA Interactome and microT-CDS were used to search the targets of circATP2B4 and miR-223, respectively. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were used to validate the above predictions. Western blot assay was performed to detect the protein expression of ATR. RESULTS: Hypoxia treatment promoted the proliferation and migration and impeded the apoptosis of PASMCs. A significant increase of circATP2B4 expression was observed in the serum of PAH patients and hypoxia-induced PASMCs compared with healthy volunteers and PASMCs under normoxia condition. MiR-223 is a target of circATP2B4, and the effects of circATP2B4 silencing on PASMCs were overturned by the transfection of anti-miR-223. ATR is a functional target of miR-223, and miR-223 inhibited the proliferation and migration while accelerated the apoptosis of PASMCs through targeting and down-regulating ATR. CircATP2B4 could up-regulate the level of ATR through sponging miR-223 in PSAMCs. CONCLUSION: CircATP2B4 potentiated hypoxia-induced proliferation and migration of PASMCs through the miR-223/ATR axis. Restoration of the level of miR-223 might be an effective therapeutic method for the treatment of PAH.
Subject(s)
Cell Movement/genetics , Cell Proliferation/genetics , Pulmonary Arterial Hypertension/genetics , Pulmonary Artery/cytology , Aged , Apoptosis/genetics , Case-Control Studies , Cell Hypoxia/physiology , Female , Gene Expression Regulation , Humans , Male , MicroRNAs/genetics , Middle Aged , Myocytes, Smooth Muscle/cytology , Plasma Membrane Calcium-Transporting ATPases/genetics , Pulmonary Arterial Hypertension/physiopathologyABSTRACT
BACKGROUND: Excessive proliferation and migration of pulmonary artery smooth muscle cells (PASMCs) play an important role in the occurrence and development of pulmonary arterial hypertension (PAH). miR-143/145 was reported to be up-regulated in the animal models and PAH patients, and deletion of miR-143/145 cluster prevented the development of hypoxia-induced pulmonary hypertension, but its underlying mechanism has not been elucidated. METHODS: qRT-PCR and Western blot were performed to detect the expressions of miR-143/145 and ATP-binding cassette transporter A1 (ABCA1) in PAH patients and PASMCs under hypoxic conditions. Cell proliferation and migration were assessed by Cell Counting Kit-8 and wound-healing assay, respectively. Luciferase reporter assay and RNA immunoprecipitation were conducted to confirm the interaction between miR-143/145 and ABCA1. Hypoxia-induced PAH rat model was established to confirm the functions of miR-143/145 in the pathogenesis of PAH and its underlying mechanism in vivo. RESULTS: miR-143 and miR-145 were up-regulated and ABCA1 was down-regulated in PAH patients and PASMCs under hypoxic conditions for different time, as well as hypoxia-induced PAH rats. miR-143/145 inhibition and ABCA1 overexpression suppressed hypoxia-induced proliferation and migration in PASMCs. ABCA1 was identified as a direct target of miR-143/145 in PASMCs. Moreover, ABCA1 partially reversed miR-143/145-mediated promotion of hypoxia-induced cell proliferation and migration in PASMCs. Furthermore, in vivo experiments confirmed that inhibition of miR-143/145 prevents hypoxia-induced pulmonary hypertension and pulmonary vascular remodeling by targeting ABCA1. CONCLUSION: miR-143/145 promoted hypoxia-induced proliferation and migration of PASMCs by targeting ABCA1, contributing to better understanding of the mechanism underlying the pathogenesis of PAH.
Subject(s)
ATP Binding Cassette Transporter 1/metabolism , Cell Movement , Cell Proliferation , Familial Primary Pulmonary Hypertension/metabolism , MicroRNAs/metabolism , Muscle, Smooth, Vascular/metabolism , Myocytes, Smooth Muscle/metabolism , ATP Binding Cassette Transporter 1/genetics , Adult , Animals , Case-Control Studies , Cell Hypoxia , Disease Models, Animal , Familial Primary Pulmonary Hypertension/genetics , Familial Primary Pulmonary Hypertension/pathology , Familial Primary Pulmonary Hypertension/physiopathology , Female , Gene Expression Regulation , HEK293 Cells , Humans , Hypoxia/genetics , Hypoxia/metabolism , Hypoxia/pathology , Hypoxia/physiopathology , Male , MicroRNAs/genetics , Middle Aged , Muscle, Smooth, Vascular/pathology , Muscle, Smooth, Vascular/physiopathology , Myocytes, Smooth Muscle/pathology , Pulmonary Artery/metabolism , Pulmonary Artery/pathology , Pulmonary Artery/physiopathology , Rats, Sprague-Dawley , Signal Transduction , Vascular RemodelingABSTRACT
The present study aimed to investigate the 5-year survival and medication status of patients with chronic heart failure (HF) and reduced ejection fraction (HFrEF) in China. This study is a single-center, retrospective study and patients with HF and a left ventricular ejection fraction (LVEF) of ≤45%, were consecutively enrolled. The study population of 685 patients was divided into two groups, namely, LVEF ≤35 (n=371) and LVEF 36-45% (n=314). The patients were followed up for a median of 31 months (range, 8-61 months) and during this period, 24% of patients receiving angiotension-converting enzyme inhibitor/angiotensin receptor blocker (ACEI/ARB) treatment and 23% of those receiving ß-blockers reached the maximum tolerated dose. Of the 191 total mortalities (28%), 127 were due to pump failure (19%) and 42 (6%) were sudden deaths. A Cox proportional hazards regression model was used to identify the variables associated with the risk of mortality. Kaplan-Meier curves and log-rank tests were used to compare the survival times of patients in the LVEF ≤35% and LVEF of 36-45% groups. The predictors of all-cause mortality were advanced age, body mass index, New York Heart Association functional class and lack of oral ß-blockers at discharge. Patients with HFrEF have poor prognoses in China, particularly those patients with an LVEF of ≤35%. Therefore, cardiologists should strive to improve the prognosis of HF among Chinese patients and focus on the importance of the practical application of HF diagnosis and treatment guidelines.
