Cytokines decrease sGC in pulmonary artery smooth muscle cells via NO-dependent and NO-independent mechanisms

2001 ◽  
Vol 280 (2) ◽  
pp. L272-L278 ◽  
Author(s):  
Masao Takata ◽  
Galina Filippov ◽  
Heling Liu ◽  
Fumito Ichinose ◽  
Stefan Janssens ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Pulmonary Artery ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
No Production ◽  
Mrna Levels ◽  
Protein Levels ◽  
Subunit Mrna ◽  
Tnf Α ◽  
Pulmonary Artery Smooth Muscle

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.

TGF-beta regulates production of NO in pulmonary artery smooth muscle cells by inhibiting expression of NOS

1995 ◽  
Vol 268 (5) ◽  
pp. L862-L867 ◽  
Author(s):  
J. Finder ◽  
W. W. Stark ◽  
D. K. Nakayama ◽  
D. Geller ◽  
K. Wasserloos ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Smooth Muscle ◽  
Pulmonary Artery ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
No Production ◽  
Tgf Beta ◽  
Inos Protein ◽  
Time Points ◽  
Pulmonary Artery Smooth Muscle

We have previously reported that a mixture of lipopolysaccharide and cytokines stimulates cultured rat pulmonary artery smooth muscle cells (RPASM) to express elevated levels of mRNA for inducible nitric oxide synthase (iNOS), and to produce large amounts of nitric oxide (NO). The current study tests the hypothesis that transforming growth factor-beta (TGF-beta) modulates this process. Accordingly, RPASM were treated with a mixture of LPS (10 micrograms/ml) and the cytokines interleukin-1 beta (5 U/ml), tumor necrosis factor-alpha (500 U/ml), and interferon-gamma (100 U/ml). In the absence of TGF-beta 1, NO production (indicated by colorimetric assay of cumulative nitrite levels at 24 h) was greatly increased, as previously observed. Under identical conditions, TGF-beta 1 caused a concentration-dependent decrease in NO production. The addition of neither excess L-arginine nor sepiapterin reversed the inhibition, indicating that the effect of TGF-beta 1 was not due to limitation of enzyme substrate or cofactor tetrahydrobiopterin, respectively. Northern and Western analyses showed that TGF-beta 1 reduced levels of iNOS mRNA and protein to baseline at all time points examined up to 24 h. Complete suppression of iNOS protein expression was evident even when TGF-beta 1 was added at postinduction time points. One mechanism of action of TGF-beta 1 was demonstrated in experiments in which degradation of iNOS protein was greatly increased by the addition of TGF-beta 1. These results demonstrate that TGF-beta 1 regulates production of NO in RPASM by inhibiting iNOS expression in part by increasing degradation of existing iNOS protein.

Mechanism of cicaprost-induced desensitization in rat pulmonary artery smooth muscle cells involves a PKA-mediated inhibition of adenylyl cyclase

2004 ◽  
Vol 287 (2) ◽  
pp. L352-L359 ◽  
Author(s):  
Anastasia Sobolewski ◽  
Karen B. Jourdan ◽  
Paul D. Upton ◽  
Lu Long ◽  
Nicholas W. Morrell
Keyword(s):  
Smooth Muscle ◽  
Pulmonary Artery ◽  
Smooth Muscle Cells ◽  
Adenylyl Cyclase ◽  
Muscle Cells ◽  
Protein Levels ◽  
Prostacyclin Receptor ◽  
Pulmonary Arterial ◽  
Pulmonary Artery Smooth Muscle

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.

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 ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Smooth Muscle ◽  
Pulmonary Artery ◽  
Smooth Muscle Cells ◽  
Noncoding Rna ◽  
Muscle Cells ◽  
Cell Cycle Distribution ◽  
Hoxa Cluster ◽  
Protein Levels ◽  
Pulmonary Artery Smooth Muscle

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.

Sign in / Sign up

Export Citation Format

Share Document