Long noncoding RNA Hoxaas3 contributes to hypoxia-induced pulmonary artery smooth muscle cell proliferation

2018 ◽  
Vol 115 (3) ◽  
pp. 647-657 ◽  
Author(s):  
Hongyue Zhang ◽  
Ying Liu ◽  
Lixin Yan ◽  
Siqi Wang ◽  
Min Zhang ◽  
...  

Abstract Aims Long noncoding RNAs (lncRNAs) are involved in the regulation of vascular smooth muscle cells and cardiovascular pathology. However, the contribution of lncRNAs to pulmonary hypertension (PH) remains largely unknown. The over-proliferation of pulmonary artery smooth muscle cells (PASMCs) causes pulmonary arterial smooth muscle hypertrophy and stenosis of the pulmonary vascular lumen, resulting in PH. Here, we investigated the biological role of a novel lncRNA, Hoxa cluster antisense RNA 3 (Hoxaas3), in the regulation of cell proliferation in PH. Methods and results Hoxaas3 was up-regulated in the lung vasculature of hypoxic mice and in PASMCs under hypoxic conditions. Histone H3 Lysine 9 acetylation of Hoxaas3 promoted gene expression. Moreover, high expression of Hoxaas3 was associated with cell proliferation and modulated cell cycle distribution by up-regulating Homeobox a3 at the mRNA and protein levels. Conclusion This study defined the role and mechanism of action of Hoxaas3 in the regulation of cell proliferation in PH, which should facilitate the development of new therapeutic strategies for the treatment of this disease.

2005 ◽  
Vol 288 (1) ◽  
pp. L202-L211 ◽  
Author(s):  
N. N. Chattergoon ◽  
F. M. D'Souza ◽  
W. Deng ◽  
H. Chen ◽  
A. L. Hyman ◽  
...  

Pulmonary hypertension is characterized by vascular remodeling involving smooth muscle cell proliferation and migration. Calcitonin gene-related peptide (CGRP) and nitric oxide (NO) are potent vasodilators, and the inhibition of aortic smooth muscle cell (ASMC) proliferation by NO has been documented, but less is known about the effects of CGRP. The mechanism by which overexpression of CGRP inhibits proliferation in pulmonary artery smooth muscle cells (PASMC) and ASMC following in vitro transfection by the gene coding for prepro-CGRP was investigated. Increased expression of p53 is known to stimulate p21, which inhibits G1 cyclin/cdk complexes, thereby inhibiting cell proliferation. We hypothesize that p53 and p21 are involved in the growth inhibitory effect of CGRP. In this study, CGRP was shown to inhibit ASMC and PASMC proliferation. In PASMC transfected with CGRP and exposed to a PKA inhibitor (PKAi), cell proliferation was restored. p53 and p21 expression increased in CGRP-treated cells but decreased in cells treated with CGRP and PKAi. PASMC treated with CGRP and a PKG inhibitor (PKGi) recovered from inhibition of proliferation induced by CGRP. ASMC treated with CGRP and then PKAi or PKGi recovered only when exposed to the PKAi and not PKGi. Although CGRP is thought to act through a cAMP-dependent pathway, cGMP involvement in the response to CGRP has been reported. It is concluded that p53 plays a role in CGRP-induced inhibition of cell proliferation and cAMP/PKA appears to mediate this effect in ASMC and PASMC, whereas cGMP appears to be involved in PASMC proliferation.


2020 ◽  
Vol 25 (1) ◽  
Author(s):  
Ying Zhang ◽  
Yongbin Chen ◽  
Guo Chen ◽  
Yingling Zhou ◽  
Hua Yao ◽  
...  

Abstract Background Abnormal proliferation of pulmonary artery smooth muscle cells (PASMCs) is a key mechanism in pulmonary arterial hypertension (PAH). Serotonin (5-hydroxytryptamine, 5-HT) can induce abnormal proliferation of PASMCs. The role of miR-361-3p in serotonin-induced abnormal PASMCs proliferation remains unclear. Methods The miR-361-3p level was analyzed in plasma from PAH patients and normal controls and in human PASMCs (hPASMCs) using RT-PCR. The hPASMCs were transfected with an miR-361-3p mimic and then treated with serotonin. Untransfected hPASMCs were used as the control. Cell proliferation was evaluated using an MTS assay and 5-ethynyl-2′-deoxyuridine (EdU) staining. The cell cycle stages were evaluated using flow cytometry. The association between miR-361-3p and serotonin transporter (SERT) was determined using a luciferase reporter assay and anti-AGO2 RNA immunoprecipitation assay. The protein expression was evaluated via western blotting. Results The miR-361-3p level was lower in plasma from PAH patients than in plasma from the any of the normal control subjects. The mean pulmonary arterial pressure, pulmonary vascular resistance and pulmonary vascular resistance index were higher in PAH patients whose miR-361-3p level was lower than the median value for patients than in those whose miR-361-3p level was higher than the median. Serotonin treatment reduced miR-361-3p expression in the hPASMCs. MiR-361-3p overexpression suppressed cell proliferation, promoted apoptosis, induced G1 arrest, and decreased the phosphorylation level of ERK1/2 in serotonin-treated hPASMCs. SERT was identified as an miR-361-3p target. Its overexpression alleviated the effect of miR-361-3p overexpression on serotonin-induced hPASMC proliferation and upregulation of phosphorylated ERK1/2. Conclusions The miR-361-3p level is lower in the plasma of PAH patients. Upregulation of miR-361-3p suppresses serotonin-induced proliferation of hPASMCs by targeting SERT. Our results suggest that miR-361-3p is a potential therapeutic target in PAH.


2004 ◽  
Vol 287 (2) ◽  
pp. L352-L359 ◽  
Author(s):  
Anastasia Sobolewski ◽  
Karen B. Jourdan ◽  
Paul D. Upton ◽  
Lu Long ◽  
Nicholas W. Morrell

Long-term infusion of prostacyclin, or its analogs, is an effective treatment for severe pulmonary arterial hypertension. However, dose escalation is often required to maintain efficacy. The aim of this study was to investigate the mechanisms of prostacyclin receptor desensitization using the prostacyclin analog cicaprost in rat pulmonary artery smooth muscle cells (PASMCs). Desensitization of the cAMP response occurred in 63 nM cicaprost after a 6-h preincubation with agonist. This desensitization was reversed 12 h after agonist removal, and resensitization was inhibited by 10 μg/ml of cycloheximide. Desensitization was heterologous since desensitization to other Gsα-adenylyl cyclase (AC)-coupled agonists, isoproterenol (1 μM), adrenomedullin (100 nM), or bradykinin (1 μM), was also reduced by preincubation with cicaprost. The reduced cAMP response to prolonged cicaprost exposure appeared to be due to inhibition of AC activity since the responses to the directly acting AC agonist forskolin (3 μM) and the selective AC5 activator NKH-477 were similarly reduced. Expression of AC2 and AC5/6 protein levels transiently decreased after 1 h of cicaprost exposure. The PKA inhibitor H-89 (1 μM) added 1 h before cicaprost preincubation (6 h, 63 nM) completely reversed cicaprost-induced desensitization, whereas the PKC inhibitor bisindolylmaleimide (100 nM) was only partly effective. Desensitization was not prevented by the Gi inhibitor pertussis toxin. In conclusion, chronic treatment of PASMCs with cicaprost induced heterologous, reversible desensitization by inhibition of AC activity. Our data suggest that heterologous Gsα desensitization by cicaprost is mediated predominantly by a PKA-inhibitable isoform of AC, most likely AC5/6.


2001 ◽  
Vol 280 (2) ◽  
pp. L272-L278 ◽  
Author(s):  
Masao Takata ◽  
Galina Filippov ◽  
Heling Liu ◽  
Fumito Ichinose ◽  
Stefan Janssens ◽  
...  

Exposure of rat pulmonary artery smooth muscle cells (rPASMC) to cytokines leads to nitric oxide (NO) production by NO synthase 2 (NOS2). NO stimulates cGMP synthesis by soluble guanylate cyclase (sGC), a heterodimer composed of α1- and β1-subunits. Prolonged exposure of rPASMC to NO decreases sGC subunit mRNA and protein levels. The objective of this study was to determine whether levels of NO produced endogenously by NOS2 are sufficient to decrease sGC expression in rPASMC. Interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) increased NOS2 mRNA levels and decreased sGC subunit mRNA levels. Exposure of rPASMC to IL-1β and TNF-α for 24 h decreased sGC subunit protein levels and NO-stimulated sGC enzyme activity.l- N 6-(1-iminoethyl)lysine (NOS2 inhibitor) or 1 H-[1,2,4]oxadiazolo-[4,3- a]quinoxalin-1-one (sGC inhibitor) partially prevented the cytokine-mediated decrease in sGC subunit mRNA levels. However, cytokines also decreased sGC subunit mRNA levels in PASMC derived from NOS2-deficient mice. These results demonstrate that levels of NO and cGMP produced in cytokine-exposed PASMC are sufficient to decrease sGC subunit mRNA levels. In addition, cytokines can decrease sGC subunit mRNA levels via NO-independent mechanisms.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
H Maruyama ◽  
S Sakai ◽  
M Ieda

Abstract Background The pathology of pulmonary arterial hypertension (PAH) indicates the abnormal outgrowth of pulmonary artery smooth muscle cells (PASMCs) of the media. Abundant expression of endothelin 1 (ET-1) is observed in vessels of PAH, and has been considered to play a pathogenic role. There are several endothelin receptors including ETA, ETB. Compared to ETA, ETB mRNA is less expressed in PASMCs from control individuals, and is reported to be increased in those from PAH patients. However, how ETB is involved in PAH remains unclear. Selexipag, a non-prostanoid IP receptor agonist, was recently authorized for treating PAH. Compared to selexipag, the active metabolite MRE-269 has a higher affinity for the IP receptor. Initial combination therapy come to be accepted as a standard strategy for this disease, although the interaction of each drug has not been discussed enough. Purpose To assess the effect of selexipag on ET-1 receptors in PASMCs. Methods We stimulated purchased human PASMCs and endothelial cells by MRE-269 (300 nM), ET-1 (100 nM) or combination of them in vitro. Quantitative PCR was performed to quantify mRNA expressions. Cell proliferation was assessed by CCK8 cell proliferation assay kit. BQ123, A192621, bosentan was used as blocker against ETA, ETB, or both, respectively. Results In PASMCs, MRE-269 increased ETA and ETB expressions 2- and 7-fold, respectively. On the other hand, it increased ETB 1.2-fold in pulmonary artery endothelial cells; ETA was not detected in those cells. After pretreatment by MRE-269, ET-1 accelerated the proliferation of PASMCs. A192621 and bosentan abrogated this proliferation. In contrast, BQ123 did not abrogate it. Conclusions In PASMCs, active selexipag metabolite MRE-269 increases ETB more strongly than ETA, resulting in accelerated cell proliferation by ET-1 predominantly via ETB. These data call for further study focused on the choice of ET-1 receptor antagonists in the case of combination therapy with selexipag.


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