Differential effects of TGF-β1 and BMP-4 on the hypoxic induction of cyclooxygenase-2 in human pulmonary artery smooth muscle cells

2004 ◽  
Vol 287 (5) ◽  
pp. L919-L927 ◽  
Author(s):  
Karen K. K. Sheares ◽  
Trina K. Jeffery ◽  
Lu Long ◽  
Xudong Yang ◽  
Nicholas W. Morrell
Keyword(s):  
Smooth Muscle ◽  
Pulmonary Artery ◽  
Smooth Muscle Cells ◽  
Critical Role ◽  
Muscle Cells ◽  
Cyclooxygenase 2 ◽  
Hypoxic Induction ◽  
Pulmonary Artery Smooth Muscle ◽  
Cox 2 ◽  
Tgf Β1

Chronic hypoxia-induced pulmonary hypertension results partly from proliferation of smooth muscle cells in small peripheral pulmonary arteries. Previously, we demonstrated that hypoxia modulates the proliferation of human peripheral pulmonary artery smooth muscle cells (PASMCs) by induction of cyclooxygenase-2 (COX-2) and production of antiproliferative prostaglandins ( 55 ). The transforming growth factor (TGF)-β superfamily plays a critical role in the regulation of pulmonary vascular remodeling, although to date an interaction with hypoxia has not been examined. We therefore investigated the pathways involved in the hypoxic induction of COX-2 in peripheral PASMCs and the contribution of TGF-β1 and bone morphogenetic protein (BMP)-4 in this response. In the present study, we demonstrate that hypoxia induces activation of p38MAPK, ERK1/2, and Akt in PASMCs and that these pathways are involved in the hypoxic regulation of COX-2. Whereas inhibition of p38MAPK or ERK1/2 activity suppressed hypoxic induction of COX-2, inhibition of the phosphoinositide 3-kinase pathway enhanced hypoxic induction of COX-2. Furthermore, exogenous TGF-β1 induced COX-2 mRNA and protein expression, and our findings demonstrate that release of TGF-β1 by PASMCs during hypoxia contributes to the hypoxic induction of COX-2 via the p38MAPK pathway. In contrast, BMP-4 inhibited the hypoxic induction of COX-2 by an MAPK-independent pathway. Together, these findings suggest that the TGF-β superfamily is part of an autocrine/paracrine system involved in the regulation of COX-2 expression in the distal pulmonary circulation, and this modulates hypoxia-induced pulmonary vascular cell proliferation.

Hypoxic Induction of Cox-2 Regulates Proliferation of Human Pulmonary Artery Smooth Muscle Cells

2002 ◽  
Vol 27 (6) ◽  
pp. 688-696 ◽  
Author(s):  
Xudong Yang ◽  
Karen K. K. Sheares ◽  
N. Davie ◽  
Paul D. Upton ◽  
Graham W. Taylor ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Pulmonary Artery ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Hypoxic Induction ◽  
Pulmonary Artery Smooth Muscle ◽  
Cox 2 ◽  
Human Pulmonary Artery

Effect of bradykinin, TGF-β1, IL-1β, and hypoxia on COX-2 expression in pulmonary artery smooth muscle cells

2002 ◽  
Vol 283 (4) ◽  
pp. L717-L725 ◽  
Author(s):  
D. A. Bradbury ◽  
R. Newton ◽  
Y.-M. Zhu ◽  
J. Stocks ◽  
L. Corbett ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Pulmonary Artery ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Prostaglandin E ◽  
Protein Synthesis Inhibitor ◽  
Cox Inhibitor ◽  
Pulmonary Artery Smooth Muscle ◽  
Cox 2 ◽  
Tgf Β1

Prostanoids are major regulators of smooth muscle function that are generated by cyclooxygenase (COX). Here we hypothesized that cytokines and mediators that regulate the pulmonary circulation would alter COX expression and prostanoid generation in pulmonary artery smooth muscle cells. Bradykinin, transforming growth factor-β1 (TGF-β1), and interleukin-1β (IL-1β) increased inducible COX-2 expression and prostaglandin E2 (PGE2) release. Transfection studies using a COX-2 promoter construct demonstrated that all three agents acted transcriptionally. Constitutive COX-1 protein expression was unchanged. The COX inhibitor indomethacin, the COX-2 inhibitor NS-398, the protein synthesis inhibitor cycloheximide, and the glucocorticoid dexamethasone abrogated the increased PGE2levels. Dexamethasone and cycloheximide prevented COX-2 induction. Hypoxia (3% O2-5% CO2-92% N2) for 24 h selectively augmented TGF-β1-stimulated PGE2 production and COX-2 induction but had no effect alone. Prolonged hypoxic culture alone for 48 and 72 h enhanced COX-2 induction and increased PGE2. These studies show that a number of stimuli are capable of inducing COX-2 in pulmonary artery smooth muscle cells. The interaction between hypoxia and TGF-β1 may be particularly relevant to pulmonary hypertension.

scholarly journals Extracellular vesicle cross-talk between pulmonary artery smooth muscle cells and endothelium during excessive TGF-β signalling: implications for PAH vascular remodelling

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Fernando de la Cuesta ◽  
Ilaria Passalacqua ◽  
Julie Rodor ◽  
Raghu Bhushan ◽  
Laura Denby ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Pulmonary Artery ◽  
Smooth Muscle Cells ◽  
Smooth Muscle Actin ◽  
Muscle Cells ◽  
Protein Markers ◽  
Vascular Remodelling ◽  
Pulmonary Artery Smooth Muscle ◽  
Tgf Β1

Abstract Background Excessive TGF-β signalling has been shown to underlie pulmonary hypertension (PAH). Human pulmonary artery smooth muscle cells (HPASMCs) can release extracellular vesicles (EVs) but their contents and significance have not yet been studied. Here, we aimed to analyse the contents and biological relevance of HPASMC-EVs and their transport to human pulmonary arterial endothelial cells (HPAECs), as well as the potential alteration of these under pathological conditions. Methods We used low-input RNA-Seq to analyse the RNA cargoes sorted into released HPASMC-EVs under basal conditions. We additionally analysed the effects of excessive TGF-β signalling, using TGF-β1 and BMP4, in the transcriptome of HPASMCs and their EVs. We then, for the first time, optimised Cre-loxP technology for its use with primary cells in vitro, directly visualising HPASMC-to-HPAEC communication and protein markers on cells taking up EVs. Furthermore we could analyse alteration of this transport with excessive TGF-β signalling, as well as by other cytokines involved in PAH: IL-1β, TNF-α and VEGFA. Results We were able to detect transcripts from 2417 genes in HPASMC-EVs. Surprisingly, among the 759 enriched in HPASMC-EVs compared to their donor cells, we found Zeb1 and 2 TGF-β superfamily ligands, GDF11 and TGF-β3. Moreover, we identified 90 genes differentially expressed in EVs from cells treated with TGF-β1 compared to EVs in basal conditions, including a subset involved in actin and ECM remodelling, among which were bHLHE40 and palladin. Finally, using Cre-loxP technology we showed cell-to-cell transfer and translation of HPASMC-EV Cre mRNA from HPASMC to HPAECs, effectively evidencing communication via EVs. Furthermore, we found increased number of smooth-muscle actin positive cells on HPAECs that took up HPASMC-EVs. The uptake and translation of mRNA was also higher in activated HPAECs, when stimulated with TGF-β1 or IL-1β. Conclusions HPASMC-EVs are enriched in RNA transcripts that encode genes that could contribute to vascular remodelling and EndoMT during development and PAH, and TGF-β1 up-regulates some that could enhance this effects. These EVs are functionally transported, increasingly taken up by activated HPAECs and contribute to EndoMT, suggesting a potential effect of HPASMC-EVs in TGF-β signalling and other related processes during PAH development.

scholarly journals Diversity of voltage-dependent K+ channels in human pulmonary artery smooth muscle cells

2004 ◽  
Vol 287 (1) ◽  
pp. L226-L238 ◽  
Author(s):  
Oleksandr Platoshyn ◽  
Carmelle V. Remillard ◽  
Ivana Fantozzi ◽  
Mehran Mandegar ◽  
Tiffany T. Sison ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Pulmonary Artery ◽  
Smooth Muscle Cells ◽  
Critical Role ◽  
Muscle Cells ◽  
Pulmonary Vasculature ◽  
Wide Range ◽  
Voltage Dependent ◽  
Pulmonary Artery Smooth Muscle ◽  
Α Subunits

Electrical excitability, which plays an important role in excitation-contraction coupling in the pulmonary vasculature, is regulated by transmembrane ion flux in pulmonary artery smooth muscle cells (PASMC). This study examined the heterogeneous nature of native voltage-dependent K+ channels in human PASMC. Both voltage-gated K+ (KV) currents and Ca2+-activated K+ (KCa) currents were observed and characterized. In cell-attached patches of PASMC bathed in Ca2+-containing solutions, depolarization elicited a wide range of K+ unitary conductances (6–290 pS). When cells were dialyzed with Ca2+-free and K+-containing solutions, depolarization elicited four components of KV currents in PASMC based on the kinetics of current activation and inactivation. Using RT-PCR, we detected transcripts of 1) 22 KV channel α-subunits (KV1.1–1.7, KV1.10, KV2.1, KV3.1, KV3.3–3.4, KV4.1–4.2, KV5.1, KV 6.1–6.3, KV9.1, KV9.3, KV10.1, and KV11.1), 2) three KV channel β-subunits (KVβ1–3), 3) four KCa channel α-subunits ( Slo-α1 and SK2–SK4), and 4) four KCa channel β-subunits (KCaβ1–4). Our results show that human PASMC exhibit a variety of voltage-dependent K+ currents with variable kinetics and conductances, which may result from various unique combinations of α- and β-subunits forming the native channels. Functional expression of these channels plays a critical role in the regulation of membrane potential, cytoplasmic Ca2+, and pulmonary vasomotor tone.

scholarly journals Hypoxia-inducible factor-1α regulates KCNMB1 expression in human pulmonary artery smooth muscle cells

2012 ◽  
Vol 302 (3) ◽  
pp. L352-L359 ◽  
Author(s):  
Yong-Tae Ahn ◽  
Yu-Mee Kim ◽  
Eloa Adams ◽  
Shu-Chen Lyu ◽  
Cristina M. Alvira ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Pulmonary Artery ◽  
Smooth Muscle Cells ◽  
Acute Hypoxia ◽  
Hypoxia Inducible Factor ◽  
Muscle Cells ◽  
Site Directed Mutagenesis ◽  
Hypoxic Induction ◽  
Pulmonary Artery Smooth Muscle ◽  
Human Pulmonary Artery

Previously, we observed that hypoxia increases the expression of the β1-subunit ( KCNMB1) of the calcium-sensitive potassium channel (BKCa). Herein, we elucidate the mechanism whereby hypoxia increases KCNMB1 expression in human pulmonary artery smooth muscle cells (hPASMC). In response to hypoxia, the expression of both the transcription factor hypoxia-inducible factor 1-α ( HIF-1α) and KCNMB1 are increased. Knockdown of HIF-1α using a shRNA plasmid blocked the hypoxic induction of KCNMB1 expression. Chromatin immunoprecipitation (ChIP) demonstrated HIF-1α binding to three discrete regions of the human KCNMB1 promoter known to contain hypoxia response elements (HREs). A KCNMB1 promoter reporter assay combined with site-directed mutagenesis identified two adjacent HREs located between −3,540 bp and −3,311 bp that are essential for the hypoxic induction of KCNMB1 promoter activity. Furthermore, additional ChIP assays demonstrated recruitment of the HIF-1α transcriptional coactivator, p300, to this same promoter region. Treatment of hPASMC with the histone deacetylase inhibitor, trichostatin, prolonged the increase in KCNMB1 observed with hypoxia, suggesting that alterations in chromatin remodeling function to limit the hypoxic induction of KCNMB1. Finally, KCNMB1 knockdown potentiated the hypoxia-induced increase in cytosolic calcium in hPASMC, highlighting the contribution of the β1-subunit in modulating vascular SMC tone in response to acute hypoxia. In conclusion, HIF-1α increases KCNMB1 expression in response to hypoxia in hPASMC by binding to two HREs located at −3,540 to −3,311 of the KCNMB1 promoter. We speculate that selective modulation of KCNMB1 expression may serve as a novel therapeutic approach to address diseases characterized by an increase in vascular tone.

scholarly journals Arterial stiffness induces remodeling phenotypes in pulmonary artery smooth muscle cells via YAP/TAZ-mediated repression of cyclooxygenase-2

2017 ◽  
Vol 313 (3) ◽  
pp. L628-L647 ◽  
Author(s):  
Paul B. Dieffenbach ◽  
Christina Mallarino Haeger ◽  
Anna Maria F. Coronata ◽  
Kyoung Moo Choi ◽  
Xaralabos Varelas ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Arterial Stiffness ◽  
Pulmonary Artery ◽  
Smooth Muscle Cells ◽  
Feedback Loop ◽  
Muscle Cells ◽  
Prostaglandin Production ◽  
Mechanical Signaling ◽  
Pulmonary Artery Smooth Muscle ◽  
Cox 2

Pulmonary arterial stiffness is an independent risk factor for mortality in pulmonary hypertension (PH) and plays a critical role in PH pathophysiology. Our laboratory has recently demonstrated arterial stiffening early in experimental PH, along with evidence for a mechanobiological feedback loop by which arterial stiffening promotes further cellular remodeling behaviors (Liu F, Haeger CM, Dieffenbach PB, Sicard D, Chrobak I, Coronata AM, Suárez Velandia MM, Vitali S, Colas RA, Norris PC, Marinković A, Liu X, Ma J, Rose CD, Lee SJ, Comhair SA, Erzurum SC, McDonald JD, Serhan CN, Walsh SR, Tschumperlin DJ, Fredenburgh LE. JCI Insight 1: e86987, 2016). Cyclooxygenase-2 (COX-2) and prostaglandin signaling have been implicated in stiffness-mediated regulation, with prostaglandin activity inversely correlated to matrix stiffness and remodeling behaviors in vitro, as well as to disease progression in rodent PH models. The mechanism by which mechanical signaling translates to reduced COX-2 activity in pulmonary vascular cells is unknown. The present work investigated the transcriptional regulators Yes-associated protein (YAP) and WW domain-containing transcription regulator 1 (WWTR1, a.k.a., TAZ), which are known drivers of downstream mechanical signaling, in mediating stiffness-induced changes in COX-2 and prostaglandin activity in pulmonary artery smooth muscle cells (PASMCs). We found that YAP/TAZ activity is increased in PAH PASMCs and experimental PH and is necessary for the development of stiffness-dependent remodeling phenotypes. Knockdown of YAP and TAZ markedly induces COX-2 expression and downstream prostaglandin production by approximately threefold, whereas overexpression of YAP or TAZ reduces COX-2 expression and prostaglandin production to near undetectable levels. Together, our findings demonstrate a stiffness-dependent YAP/TAZ-mediated positive feedback loop that drives remodeling phenotypes in PASMCs via reduced COX-2 and prostaglandin activity. The ability to interrupt this critical mechanobiological feedback loop and enhance local prostaglandin activity via manipulation of YAP/TAZ signaling presents a highly attractive novel strategy for the treatment of PH.

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