scholarly journals Upregulation of Piezo1 (Piezo Type Mechanosensitive Ion Channel Component 1) Enhances the Intracellular Free Calcium in Pulmonary Arterial Smooth Muscle Cells From Idiopathic Pulmonary Arterial Hypertension Patients

Hypertension ◽  
2021 ◽  
Author(s):  
Jing Liao ◽  
Wenju Lu ◽  
Yuqin Chen ◽  
Xin Duan ◽  
Chenting Zhang ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Intracellular Calcium ◽  
Calcium Release ◽  
Free Calcium ◽  
Mechanosensitive Ion Channel ◽  
Pulmonary Arterial ◽  
Arterial Smooth Muscle Cells ◽  
Pulmonary Arterial Smooth Muscle

Emerging studies have reported the mechanosensitive Piezo1 (piezo type mechanosensitive ion channel component 1) plays essential roles in regulating the vascular tone through mechanistic actions on intracellular calcium homeostasis. However, the specific roles of Piezo1 in pulmonary vessels remain incompletely understood. We aim to investigate whether and how Piezo1 regulates the intracellular calcium homeostasis in human pulmonary arterial smooth muscle cells (PASMCs) under normal and pulmonary arterial hypertension (PAH) conditions. Cultured human PASMCs isolated from both control donors and idiopathic PAH patients were used as cell models. Fura-2 based intracellular calcium imaging was performed to measure the intracellular free calcium concentration ([Ca 2+ ] i ). Results showed that activation of Piezo1 by Yoda1 increases [Ca 2+ ] i by inducing both intracellular calcium release from internal calcium stores through the intracellular (intra-) Piezo1 localized at the subcellular organelles, including endoplasmic reticulum/sarcoplasmic reticulum, mitochondria, and nucleus; as well as extracellular calcium influx through the plasma membrane-localized Piezo1 in a mechanism independent of the store-operated calcium entry. Moreover, the Piezo1-mediated increase of [Ca 2+ ] i is linked to increased contraction and proliferation of PASMCs. Yoda1 induces dose-dependent vasocontraction in endothelium-denuded rat intrapulmonary arteries. Significant upregulation and increased activity of Piezo1 were observed in idiopathic PAH-PASMCs versus donor-PASMCs, contributing to the increased [Ca 2+ ] i and excessive proliferation of idiopathic PAH-PASMCs. In summary, Piezo1 mediates the increase of [Ca 2+ ] i by triggering both intracellular calcium release and extracellular influx. The enhanced Piezo1 expression and activity accounts, at least partially, for the abnormally elevated [Ca 2+ ] i and proliferation in idiopathic PAH-PASMCs.

scholarly journals Vital Roles of Gremlin‐1 in Pulmonary Arterial Hypertension Induced by Systemic‐to‐Pulmonary Shunts

2020 ◽  
Vol 9 (15) ◽  
Author(s):  
Liukun Meng ◽  
Xiao Teng ◽  
Yao Liu ◽  
Chao Yang ◽  
Shengwei Wang ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Arterial Smooth Muscle ◽  
Pulmonary Arterial ◽  
Arterial Smooth Muscle Cells ◽  
Pulmonary Arterial Smooth Muscle ◽  
Gremlin 1

Background Heterozygous mutation in BMP (bone morphogenetic protein) receptor 2 is rare, but BMP cascade suppression is common in congenital heart disease–associated pulmonary arterial hypertension (CHD‐PAH); however, the underling mechanism of BMP cascade suppression independent of BMP receptor 2 mutation is unknown. Methods and Results Pulmonary hypertensive status observed in CHD‐PAH was surgically reproduced in rats. Gremlin‐1 expression was increased, but BMP cascade was suppressed, in lungs from CHD‐PAH patients and shunted rats, whereas shunt correction retarded these trends in rats. Immunostaining demonstrated increased gremlin‐1 was mainly in the endothelium and media of remodeled pulmonary arteries. However, mechanical stretch time‐ and amplitude‐dependently stimulated gremlin‐1 secretion and suppressed BMP cascade in distal pulmonary arterial smooth muscle cells from healthy rats. Under static condition, gremlin‐1 significantly promoted the proliferation and inhibited the apoptosis of distal pulmonary arterial smooth muscle cells from healthy rats via BMP cascade. Furthermore, plasma gremlin‐1 closely correlated with hemodynamic parameters in CHD‐PAH patients and shunted rats. Conclusions Serving as an endogenous antagonist of BMP cascade, the increase of gremlin‐1 in CHD‐PAH may present a reasonable mechanism explanation for BMP cascade suppression independent of BMP receptor 2 mutation.

scholarly journals PDGF enhances store-operated Ca2+ entry by upregulating STIM1/Orai1 via activation of Akt/mTOR in human pulmonary arterial smooth muscle cells

2012 ◽  
Vol 302 (2) ◽  
pp. C405-C411 ◽  
Author(s):  
Aiko Ogawa ◽  
Amy L. Firth ◽  
Kimberly A. Smith ◽  
Mary V. Maliakal ◽  
Jason X.-J. Yuan
Keyword(s):  
Cell Proliferation ◽  
Smooth Muscle ◽  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Arterial Smooth Muscle ◽  
Pulmonary Arterial ◽  
Arterial Smooth Muscle Cells ◽  
Pulmonary Arterial Smooth Muscle

Platelet-derived growth factor (PDGF) and its receptor are known to be substantially elevated in lung tissues and pulmonary arterial smooth muscle cells (PASMC) isolated from patients and animals with pulmonary arterial hypertension. PDGF has been shown to phosphorylate and activate Akt and mammalian target of rapamycin (mTOR) in PASMC. In this study, we investigated the role of PDGF-mediated activation of Akt signaling in the regulation of cytosolic Ca2+ concentration and cell proliferation. PDGF activated the Akt/mTOR pathway and, subsequently, enhanced store-operated Ca2+ entry (SOCE) and cell proliferation in human PASMC. Inhibition of Akt attenuated the increase in cytosolic Ca2+ concentration due to both SOCE and PASMC proliferation. This effect correlated with a significant downregulation of stromal interacting molecule (STIM) and Orai, proposed molecular correlates for SOCE in many cell types. The data from this study present a novel pathway for the regulation of Ca2+ signaling and PASMC proliferation involving activation of Akt in response to upregulated expression of PDGF. Targeting this pathway may lead to the development of a novel therapeutic option for the treatment of pulmonary arterial hypertension.

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