Functional linkage of Na+-Ca2+-exchanger to sarco/endoplasmic reticulum Ca2+ pump in coronary artery: Comparison of smooth muscle and endothelial cells

Kim A. Davis, Sue E. Samson, Kaitlin E. Hammel, L. Kiss, F. Fülöp, Ashok K. Grover

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

An increase in cytosolic Ca2+ concentration in coronary artery smooth muscle causes a contraction but in endothelium it causes relaxation. Na+-Ca2+-exchanger (NCX) may play a role in Ca 2+ dynamics in both the cell types. Here, the NCX-mediated 45Ca2+ uptake was compared in Na+-loaded pig coronary artery smooth muscle and endothelial cells. In both the cell types, this uptake was inhibited by KB-R7943, SEA 0400 and by monensin, but not by cariporide. Prior loading of the cells with the Ca2+ chelator BAPTA increased the NCX-mediated 45Ca2+ uptake in smooth muscle but not in endothelial cells. In the presence or absence of BAPTA loading, the Na+-mediated 45Ca2+ uptake was greater in endothelial than in smooth muscle cells. In smooth muscle cells without BAPTA loading, thapsigargin diminished the NCX-mediated 45Ca2+ entry. This effect was not observed in endothelial cells or in either cell type after BAPTA loading. The results in the smooth muscle cells are consistent with a limited diffusional space model in which the NCX-mediated 45Ca 2+ uptake was enhanced by chelation of cytosolic Ca2+ or by its sequestration by the sarco/endoplasmic reticulum Ca2+ pump (SERCA). They suggest a functional linkage between NCX and SERCA in the smooth muscle but not in the endothelial cells. The concept of a linkage between NCX and SERCA in smooth muscle was also confirmed by similar distribution of NCX and SERCA2 proteins when detergent-treated microsomes were fractionated by flotation on sucrose density gradients. Thus, the coronary artery smooth muscle and endothelial cells differ not only in the relative activities of NCX but also in its functional linkage to SERCA.

Original languageEnglish
Pages (from-to)1775-1783
Number of pages9
JournalJournal of Cellular and Molecular Medicine
Volume13
Issue number8 B
DOIs
Publication statusPublished - Aug 2009

Fingerprint

Endoplasmic Reticulum
Smooth Muscle Myocytes
Coronary Vessels
Endothelial Cells
Smooth Muscle
Space Simulation
Monensin
Thapsigargin
Chelating Agents
Microsomes
Detergents
Endothelium
Sucrose
Swine
1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid
Proteins

Keywords

  • BAPTA
  • Coupling
  • Lipid rafts
  • NCX
  • SERCA
  • Thapsigargin

ASJC Scopus subject areas

  • Cell Biology
  • Molecular Medicine

Cite this

Functional linkage of Na+-Ca2+-exchanger to sarco/endoplasmic reticulum Ca2+ pump in coronary artery : Comparison of smooth muscle and endothelial cells. / Davis, Kim A.; Samson, Sue E.; Hammel, Kaitlin E.; Kiss, L.; Fülöp, F.; Grover, Ashok K.

In: Journal of Cellular and Molecular Medicine, Vol. 13, No. 8 B, 08.2009, p. 1775-1783.

Research output: Contribution to journalArticle

@article{b12806e5c47645f8abc9c4ac8fff6bff,
title = "Functional linkage of Na+-Ca2+-exchanger to sarco/endoplasmic reticulum Ca2+ pump in coronary artery: Comparison of smooth muscle and endothelial cells",
abstract = "An increase in cytosolic Ca2+ concentration in coronary artery smooth muscle causes a contraction but in endothelium it causes relaxation. Na+-Ca2+-exchanger (NCX) may play a role in Ca 2+ dynamics in both the cell types. Here, the NCX-mediated 45Ca2+ uptake was compared in Na+-loaded pig coronary artery smooth muscle and endothelial cells. In both the cell types, this uptake was inhibited by KB-R7943, SEA 0400 and by monensin, but not by cariporide. Prior loading of the cells with the Ca2+ chelator BAPTA increased the NCX-mediated 45Ca2+ uptake in smooth muscle but not in endothelial cells. In the presence or absence of BAPTA loading, the Na+-mediated 45Ca2+ uptake was greater in endothelial than in smooth muscle cells. In smooth muscle cells without BAPTA loading, thapsigargin diminished the NCX-mediated 45Ca2+ entry. This effect was not observed in endothelial cells or in either cell type after BAPTA loading. The results in the smooth muscle cells are consistent with a limited diffusional space model in which the NCX-mediated 45Ca 2+ uptake was enhanced by chelation of cytosolic Ca2+ or by its sequestration by the sarco/endoplasmic reticulum Ca2+ pump (SERCA). They suggest a functional linkage between NCX and SERCA in the smooth muscle but not in the endothelial cells. The concept of a linkage between NCX and SERCA in smooth muscle was also confirmed by similar distribution of NCX and SERCA2 proteins when detergent-treated microsomes were fractionated by flotation on sucrose density gradients. Thus, the coronary artery smooth muscle and endothelial cells differ not only in the relative activities of NCX but also in its functional linkage to SERCA.",
keywords = "BAPTA, Coupling, Lipid rafts, NCX, SERCA, Thapsigargin",
author = "Davis, {Kim A.} and Samson, {Sue E.} and Hammel, {Kaitlin E.} and L. Kiss and F. F{\"u}l{\"o}p and Grover, {Ashok K.}",
year = "2009",
month = "8",
doi = "10.1111/j.1582-4934.2008.00480.x",
language = "English",
volume = "13",
pages = "1775--1783",
journal = "Journal of Cellular and Molecular Medicine",
issn = "1582-1838",
publisher = "Wiley-Blackwell",
number = "8 B",

}

TY - JOUR

T1 - Functional linkage of Na+-Ca2+-exchanger to sarco/endoplasmic reticulum Ca2+ pump in coronary artery

T2 - Comparison of smooth muscle and endothelial cells

AU - Davis, Kim A.

AU - Samson, Sue E.

AU - Hammel, Kaitlin E.

AU - Kiss, L.

AU - Fülöp, F.

AU - Grover, Ashok K.

PY - 2009/8

Y1 - 2009/8

N2 - An increase in cytosolic Ca2+ concentration in coronary artery smooth muscle causes a contraction but in endothelium it causes relaxation. Na+-Ca2+-exchanger (NCX) may play a role in Ca 2+ dynamics in both the cell types. Here, the NCX-mediated 45Ca2+ uptake was compared in Na+-loaded pig coronary artery smooth muscle and endothelial cells. In both the cell types, this uptake was inhibited by KB-R7943, SEA 0400 and by monensin, but not by cariporide. Prior loading of the cells with the Ca2+ chelator BAPTA increased the NCX-mediated 45Ca2+ uptake in smooth muscle but not in endothelial cells. In the presence or absence of BAPTA loading, the Na+-mediated 45Ca2+ uptake was greater in endothelial than in smooth muscle cells. In smooth muscle cells without BAPTA loading, thapsigargin diminished the NCX-mediated 45Ca2+ entry. This effect was not observed in endothelial cells or in either cell type after BAPTA loading. The results in the smooth muscle cells are consistent with a limited diffusional space model in which the NCX-mediated 45Ca 2+ uptake was enhanced by chelation of cytosolic Ca2+ or by its sequestration by the sarco/endoplasmic reticulum Ca2+ pump (SERCA). They suggest a functional linkage between NCX and SERCA in the smooth muscle but not in the endothelial cells. The concept of a linkage between NCX and SERCA in smooth muscle was also confirmed by similar distribution of NCX and SERCA2 proteins when detergent-treated microsomes were fractionated by flotation on sucrose density gradients. Thus, the coronary artery smooth muscle and endothelial cells differ not only in the relative activities of NCX but also in its functional linkage to SERCA.

AB - An increase in cytosolic Ca2+ concentration in coronary artery smooth muscle causes a contraction but in endothelium it causes relaxation. Na+-Ca2+-exchanger (NCX) may play a role in Ca 2+ dynamics in both the cell types. Here, the NCX-mediated 45Ca2+ uptake was compared in Na+-loaded pig coronary artery smooth muscle and endothelial cells. In both the cell types, this uptake was inhibited by KB-R7943, SEA 0400 and by monensin, but not by cariporide. Prior loading of the cells with the Ca2+ chelator BAPTA increased the NCX-mediated 45Ca2+ uptake in smooth muscle but not in endothelial cells. In the presence or absence of BAPTA loading, the Na+-mediated 45Ca2+ uptake was greater in endothelial than in smooth muscle cells. In smooth muscle cells without BAPTA loading, thapsigargin diminished the NCX-mediated 45Ca2+ entry. This effect was not observed in endothelial cells or in either cell type after BAPTA loading. The results in the smooth muscle cells are consistent with a limited diffusional space model in which the NCX-mediated 45Ca 2+ uptake was enhanced by chelation of cytosolic Ca2+ or by its sequestration by the sarco/endoplasmic reticulum Ca2+ pump (SERCA). They suggest a functional linkage between NCX and SERCA in the smooth muscle but not in the endothelial cells. The concept of a linkage between NCX and SERCA in smooth muscle was also confirmed by similar distribution of NCX and SERCA2 proteins when detergent-treated microsomes were fractionated by flotation on sucrose density gradients. Thus, the coronary artery smooth muscle and endothelial cells differ not only in the relative activities of NCX but also in its functional linkage to SERCA.

KW - BAPTA

KW - Coupling

KW - Lipid rafts

KW - NCX

KW - SERCA

KW - Thapsigargin

UR - http://www.scopus.com/inward/record.url?scp=72949116173&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=72949116173&partnerID=8YFLogxK

U2 - 10.1111/j.1582-4934.2008.00480.x

DO - 10.1111/j.1582-4934.2008.00480.x

M3 - Article

C2 - 18752635

AN - SCOPUS:72949116173

VL - 13

SP - 1775

EP - 1783

JO - Journal of Cellular and Molecular Medicine

JF - Journal of Cellular and Molecular Medicine

SN - 1582-1838

IS - 8 B

ER -