scholarly journals Effects of hypercapnia and hypocapnia on [Ca2+]i mobilization in human pulmonary artery endothelial cells

2001 ◽  
Vol 90 (6) ◽  
pp. 2094-2100 ◽  
Author(s):  
Kazumi Nishio ◽  
Yukio Suzuki ◽  
Kei Takeshita ◽  
Takuya Aoki ◽  
Hiroyasu Kudo ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Pulmonary Artery ◽  
Vascular Tone ◽  
Extracellular Ph ◽  
Hypercapnic Acidosis ◽  
Extracellular Medium ◽  
Vasoactive Substances ◽  
Intracellular Ca ◽  
Human Pulmonary Artery ◽  
Hypocapnic Alkalosis

The hydrogen ion is an important factor in the alteration of vascular tone in pulmonary circulation. Endothelial cells modulate vascular tone by producing vasoactive substances such as prostacyclin (PGI2) through a process depending on intracellular Ca2+ concentration ([Ca2+]i). We studied the influence of CO2-related pH changes on [Ca2+]iand PGI2 production in human pulmonary artery endothelial cells (HPAECs). Hypercapnic acidosis appreciably increased [Ca2+]i from 112 ± 24 to 157 ± 38 nmol/l. Intracellular acidification at a normal extracellular pH increased [Ca2+]i comparable to that observed during hypercapnic acidosis. The hypercapnia-induced increase in [Ca2+]i was unchanged by the removal of Ca2+ from the extracellular medium or by the depletion of thapsigargin-sensitive intracellular Ca2+ stores. Hypercapnic acidosis may thus release Ca2+ from pH-sensitive but thapsigargin-insensitive intracellular Ca2+ stores. Hypocapnic alkalosis caused a fivefold increase in [Ca2+]i compared with hypercapnic acidosis. Intracellular alkalinization at a normal extracellular pH did not affect [Ca2+]i. The hypocapnia-evoked increase in [Ca2+]i was decreased from 242 ± 56 to 50 ± 32 nmol/l by the removal of extracellular Ca2+. The main mechanism affecting the hypocapnia-dependent [Ca2+]i increase was thought to be the augmented influx of extracellular Ca2+ mediated by extracellular alkalosis. Hypercapnic acidosis caused little change in PGI2 production, but hypocapnic alkalosis increased it markedly. In conclusion, both hypercapnic acidosis and hypocapnic alkalosis increase [Ca2+]i in HPAECs, but the mechanisms and pathophysiological significance of these increases may differ qualitatively.

scholarly journals Thrombin-mediated increases in cytosolic [Ca2+] involve different mechanisms in human pulmonary artery smooth muscle and endothelial cells

2008 ◽  
Vol 295 (6) ◽  
pp. L1048-L1055 ◽  
Author(s):  
Richard S. Sacks ◽  
Amy L. Firth ◽  
Carmelle V. Remillard ◽  
Negin Agange ◽  
Jocelyn Yau ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Pulmonary Artery ◽  
Calcium Influx ◽  
Dynamic Balance ◽  
Cyclopiazonic Acid ◽  
Cell Types ◽  
Intracellular Ca ◽  
Pulmonary Artery Smooth Muscle ◽  
Human Pulmonary Artery

Thrombin is a procoagulant inflammatory agonist that can disrupt the endothelium-lumen barrier in the lung by causing contraction of endothelial cells and promote pulmonary cell proliferation. Both contraction and proliferation require increases in cytosolic Ca2+ concentration ([Ca2+]cyt). In this study, we compared the effect of thrombin on Ca2+ signaling in human pulmonary artery smooth muscle (PASMC) and endothelial (PAEC) cells. Thrombin increased the [Ca2+]cyt in both cell types; however, the transient response was significantly higher and recovered quicker in the PASMC, suggesting different mechanisms may contribute to thrombin-mediated increases in [Ca2+]cyt in these cell types. Depletion of intracellular stores with cyclopiazonic acid (CPA) in the absence of extracellular Ca2+ induced calcium transients representative of those observed in response to thrombin in both cell types. Interestingly, CPA pretreatment significantly attenuated thrombin-induced Ca2+ release in PASMC; this attenuation was not apparent in PAEC, indicating that a PAEC-specific mechanism was targeted by thrombin. Treatment with a combination of CPA, caffeine, and ryanodine also failed to abolish the thrombin-induced Ca2+ transient in PAEC. Notably, thrombin-induced receptor-mediated calcium influx was still observed in PASMC after CPA pretreatment in the presence of extracellular Ca2+. Ca2+ oscillations were triggered by thrombin in PASMC resulting from a balance of extracellular Ca2+ influx and Ca2+ reuptake by the sarcoplasmic reticulum. The data show that thrombin induces increases in intracellular calcium in PASMC and PAEC with a distinct CPA-, caffeine-, and ryanodine-insensitive release existing only in PAEC. Furthermore, a dynamic balance between Ca2+ influx, intracellular Ca2+ release, and reuptake underlie the Ca2+ transients evoked by thrombin in some PASMC. Understanding of such mechanisms will provide an important insight into thrombin-mediated vascular injury during hypertension.

Endogenously released ATP mediates shear stress-induced Ca2+influx into pulmonary artery endothelial cells

2003 ◽  
Vol 285 (2) ◽  
pp. H793-H803 ◽  
Author(s):  
Kimiko Yamamoto ◽  
Takaaki Sokabe ◽  
Norihiko Ohura ◽  
Hideki Nakatsuka ◽  
Akira Kamiya ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Pulmonary Artery ◽  
Atp Release ◽  
Atpase Inhibitor ◽  
Intracellular Ca ◽  
Human Pulmonary Artery ◽  
Stress Dependent ◽  
Dose Dependent ◽  
Balanced Solution

The mechanisms by which flow-imposed shear stress elevates intracellular Ca2+in cultured endothelial cells (ECs) are not fully understood. Here we report finding that endogenously released ATP contributes to shear stress-induced Ca2+responses. Application of flow of Hanks' balanced solution to human pulmonary artery ECs (HPAECs) elicited shear stress-dependent increases in Ca2+concentrations. Chelation of extracellular Ca2+with EGTA completely abolished the Ca2+responses, whereas the phospholipase C inhibitor U-73122 or the Ca2+-ATPase inhibitor thapsigargin had no effect, which thereby indicates that the response was due to the influx of extracellular Ca2+. The Ca2+influx was significantly suppressed by apyrase, which degrades ATP, or antisense oligonucleotide targeted to P2X4purinoceptors. A luciferase luminometric assay showed that shear stress induced dose-dependent release of ATP. When the ATP release was inhibited by the ATP synthase inhibitors angiostatin or oligomycin, the Ca2+influx was markedly suppressed but was restored by removal of these inhibitors or addition of extracellular ATP. These results suggest that shear stress stimulates HPAECs to release ATP, which activates Ca2+influx via P2X4receptors.

scholarly journals Histamine-mediated increases in cytosolic [Ca2+] involve different mechanisms in human pulmonary artery smooth muscle and endothelial cells

2006 ◽  
Vol 290 (2) ◽  
pp. C325-C336 ◽  
Author(s):  
Joseph R. H. Mauban ◽  
Katherine Wilkinson ◽  
Christian Schach ◽  
Jason X.-J. Yuan
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Pulmonary Artery ◽  
Solution Treatment ◽  
Cyclopiazonic Acid ◽  
Free Solution ◽  
Intracellular Ca ◽  
Pulmonary Artery Smooth Muscle ◽  
Human Pulmonary Artery ◽  
Stimulation Of

Agonist stimulation of human pulmonary artery smooth muscle cells (PASMC) and endothelial cells (PAEC) with histamine showed similar spatiotemporal patterns of Ca2+ release. Both sustained elevation and oscillatory patterns of changes in cytosolic Ca2+ concentration ([Ca2+]cyt) were observed in the absence of extracellular Ca2+. Capacitative Ca2+ entry (CCE) was induced in PASMC and PAEC by passive depletion of intracellular Ca2+ stores with 10 μM cyclopiazonic acid (CPA; 15–30 min). The pyrazole derivative BTP2 inhibited CPA-activated Ca2+ influx, suggesting that depletion of CPA-sensitive internal stores is sufficient to induce CCE in both PASMC and PAEC. The recourse of histamine-mediated Ca2+ release was examined after exposure of cells to CPA, thapsigargin, caffeine, ryanodine, FCCP, or bafilomycin. In PASMC bathed in Ca2+-free solution, treatment with CPA almost abolished histamine-induced rises in [Ca2+]cyt. In PAEC bathed in Ca2+-free solution, however, treatment with CPA eliminated histamine-induced sustained and oscillatory rises in [Ca2+]cyt but did not affect initial transient increase in [Ca2+]cyt. Furthermore, treatment of PAEC with a combination of CPA (or thapsigargin) and caffeine (and ryanodine), FCCP, or bafilomycin did not abolish histamine-induced transient [Ca2+]cyt increases. These observations indicate that 1) depletion of CPA-sensitive stores is sufficient to cause CCE in both PASMC and PAEC; 2) induction of CCE in PAEC does not require depletion of all internal Ca2+ stores; 3) the histamine-releasable internal stores in PASMC are mainly CPA-sensitive stores; 4) PAEC, in addition to a CPA-sensitive functional pool, contain other stores insensitive to CPA, thapsigargin, caffeine, ryanodine, FCCP, and bafilomycin; and 5) although the CPA-insensitive stores in PAEC may not contribute to CCE, they contribute to histamine-mediated Ca2+ release.

scholarly journals Fenfluramine-Induced Gene Dysregulation in Human Pulmonary Artery Smooth Muscle and Endothelial Cells

2011 ◽  
Vol 1 (3) ◽  
pp. 405-418 ◽  
Author(s):  
Weijuan Yao ◽  
Wenbo Mu ◽  
Amy Zeifman ◽  
Michelle Lofti ◽  
Carmelle V. Remillard ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Pulmonary Artery ◽  
Gene Dysregulation ◽  
Pulmonary Artery Smooth Muscle ◽  
Human Pulmonary Artery

Abstract 218: Fibrinolytic Reactivity of Venous Endothelial Cells from Different Vascular Beds

2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Neil G Kumar ◽  
Elisa Roztocil ◽  
John P Cullen ◽  
David L Gillespie
Keyword(s):  
Endothelial Cells ◽  
Pulmonary Artery ◽  
Cell Types ◽  
Iliac Vein ◽  
Vein Thrombosis ◽  
Cellular Expression ◽  
Artery Embolism ◽  
Vascular Beds ◽  
Human Pulmonary Artery ◽  
Pai 1

Objective: Little is known about the molecular biology of endothelial cells from different venous vascular beds. As a result, our treatment of deep vein thrombosis (DVT) and pulmonary artery embolism (PE) remain identical. PAI-1 and tPA are important regulators of thrombosis and fibrinolysis, while ICAM-1 is known to bind fibrinogen. Here, we aim to investigate differences in fibrinolytic reactivity between human iliac vein endothelial cells (HIVECs) and human pulmonary artery endothelial cells (HPAECs). Methods: Confluent HIVECs and HPAECs, passages 3 - 6, were cultured in the absence or presence of TNFα (10 ng/mL) for 24 hours. Cellular expression of tPA and PAI-1 as analyzed by Western blot analysis and ICAM-1 as analyzed by flow cytometry were compared to controls. Results: Following TNFα stimulation, PAI-1 was upregulated in both HPAECs and HIVECs, however the upregulation observed in HPAECs was approximately 9-fold the increase observed in HIVECs (relative expression: 3.23 ± 0.52 vs 1.26 ± 0.27, n = 3, p < 0.05). While TNFα had no effect on tPA expression in HIVECs, tPA expression in HPAECS was upregulated by 33% (n = 3, p < 0.05). Although TNFα stimulation increased the number of ICAM-1 positive to approximately 100% in both cell types, a 3-fold greater increase in the Mean Fluorescence Intensity (MFI) was observed in HIVECs when compared to HPAECs (relative MFI: 69.28 ± 13.58 vs 21.92 ± 7.22, n = 3, p <0.05). Conclusions: HPAECs and HIVECs react differently in terms of fibrinolytic potential when challenged with a cytokine associated with systemic inflammation, such as in DVT and PE. These findings suggest that endothelial cells from distinct venous vascular beds may differentially regulate the fibrinolytic pathway, thus demonstrating unique properties of the deep veins and the pulmonary artery to respond to thromboembolism.

Isolation and maintenance of human pulmonary artery endothelial cells in culture isolated from transplant donors

1994 ◽  
Vol 267 (4) ◽  
pp. L406-L413 ◽  
Author(s):  
G. A. Visner ◽  
E. D. Staples ◽  
S. E. Chesrown ◽  
E. R. Block ◽  
D. S. Zander ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Pulmonary Artery ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Immunofluorescent Staining ◽  
Northern Analysis ◽  
Pulmonary Vasculature ◽  
Pulmonary Vascular Disease ◽  
Antigen Uptake ◽  
Human Pulmonary Artery

Even though endothelial cells from different locations have similarities, there are potential morphological and functional differences between cells from different vascular regions, as well as between species. Our laboratory is interested in studying the molecular regulation of vasoactive substances in pulmonary vasculature. Therefore, we have developed reproducible methodology to isolate and maintain cultures of human pulmonary artery endothelial cells. The major innovation has been the employment of sections of pulmonary artery from heart transplant donors, from which endothelial cells are isolated. Cell monolayers were identified as endothelial cells by phase-contrast microscopy. Representative dishes of cells were further characterized by indirect immunofluorescent staining for factor VIII antigen, uptake of acetylated low-density lipoprotein, and electron microscopy. These cells were also evaluated for the expression of endothelin-1 (ET-1), a vasoactive 21-amino acid peptide derived from endothelial cells. The cells expressed ET-1 peptide and mRNA as determined by radioimmunoassay and Northern analysis, respectively. We also demonstrated that these cells are useful in transient transfection experiments for potential evaluation of promoter elements. The availability and relevance of these cells provide an important investigative tool for studies on human pulmonary vascular disease.

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