Intracellular calcium requirements for β1 integrin activation

Mark Rowin, Ralph E. Whatley, Ted Yednock, John F. Bohnsack

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

Human polymorphonuclear leukocytes (PMNs) express β1 integrins that mediate adhesion to extracellular matrix proteins following stimulation with agonists that induce an increase in intracellular calcium. The purpose of these studies was to determine the contribution made by alterations in intracellular calcium ([Ca ++ ](i)) to inside-out activation of pi integrins using dimethyl sulfoxide (DMSO)-differentiated granulocytic HL60 cells as a model of human PMNs. Activation of β1 integrins was determined by measuring the expression of an activation-dependent epitope on the β1 subunit that is recognized by monoclonal antibody (mAb) 15/ 7. Exposure of granulocytic HL60 cells to calcium ionophore ionomycin (800 nM) alone did not increase the binding of mAb 15/7 to the cell surface, nor did it increase β1 integrin-mediated adhesion of the cells to fibronectin. Similarly, exposure of the cells to the direct protein kinase C (PKC) activator, dioclanoylglycerol (di-C 8 ) at 100 μM, neither increased binding of mAb 15/7 to these cells nor adhesion to fibronectin. Simultaneous addition of di-C 8 and ionomycin, however, caused a significant increase in the expression of the 15/7 epitope and cell adhesion, suggesting synergy between elevating [Ca ++ ](i) and stimulating PKC in β1 integrin activation. Chelation of [Ca ++ ]((i)) with Quin-2 and EGTA reduced both basal (unstimulated) expression of the 15/7 epitope and basal adhesion of granulocytic HL60 cells to fibronectin. In addition, chelation of [Ca ++ ](i) caused a significant decrease in 15/7 binding and adhesion stimulated by low (1 ng/ml) concentrations of phorbol myristate acetate (PMA). The inhibitory effect of [Ca ++ ](i) chelation on β1 integrin activation was reversed by repleting [Ca ++ ](i) with ionomycin in a Ca ++ -containing buffer, or by the addition of higher concentrations of PMA (10 ng/ml). These data suggest a role for [Ca ++ ](i) in inside-out activation of pi integrins, probably through a synergistic effect with PKC activation.

Original languageEnglish (US)
Pages (from-to)193-202
Number of pages10
JournalJournal of cellular physiology
Volume175
Issue number2
DOIs
StatePublished - May 1 1998

Fingerprint

Integrins
Chemical activation
Calcium
Adhesion
Ionomycin
HL-60 Cells
Chelation
Fibronectins
Cell Adhesion
Protein Kinase C
Epitopes
Monoclonal Antibodies
Tetradecanoylphorbol Acetate
Calcium Ionophores
Extracellular Matrix Proteins
Egtazic Acid
Cell adhesion
Dimethyl Sulfoxide
Buffers
Neutrophils

All Science Journal Classification (ASJC) codes

  • Physiology
  • Clinical Biochemistry
  • Cell Biology

Cite this

Intracellular calcium requirements for β1 integrin activation. / Rowin, Mark; Whatley, Ralph E.; Yednock, Ted; Bohnsack, John F.

In: Journal of cellular physiology, Vol. 175, No. 2, 01.05.1998, p. 193-202.

Research output: Contribution to journalArticle

Rowin, Mark ; Whatley, Ralph E. ; Yednock, Ted ; Bohnsack, John F. / Intracellular calcium requirements for β1 integrin activation. In: Journal of cellular physiology. 1998 ; Vol. 175, No. 2. pp. 193-202.
@article{72747677c99f4f3a8545dc8c5bdc05b0,
title = "Intracellular calcium requirements for β1 integrin activation",
abstract = "Human polymorphonuclear leukocytes (PMNs) express β1 integrins that mediate adhesion to extracellular matrix proteins following stimulation with agonists that induce an increase in intracellular calcium. The purpose of these studies was to determine the contribution made by alterations in intracellular calcium ([Ca ++ ](i)) to inside-out activation of pi integrins using dimethyl sulfoxide (DMSO)-differentiated granulocytic HL60 cells as a model of human PMNs. Activation of β1 integrins was determined by measuring the expression of an activation-dependent epitope on the β1 subunit that is recognized by monoclonal antibody (mAb) 15/ 7. Exposure of granulocytic HL60 cells to calcium ionophore ionomycin (800 nM) alone did not increase the binding of mAb 15/7 to the cell surface, nor did it increase β1 integrin-mediated adhesion of the cells to fibronectin. Similarly, exposure of the cells to the direct protein kinase C (PKC) activator, dioclanoylglycerol (di-C 8 ) at 100 μM, neither increased binding of mAb 15/7 to these cells nor adhesion to fibronectin. Simultaneous addition of di-C 8 and ionomycin, however, caused a significant increase in the expression of the 15/7 epitope and cell adhesion, suggesting synergy between elevating [Ca ++ ](i) and stimulating PKC in β1 integrin activation. Chelation of [Ca ++ ]((i)) with Quin-2 and EGTA reduced both basal (unstimulated) expression of the 15/7 epitope and basal adhesion of granulocytic HL60 cells to fibronectin. In addition, chelation of [Ca ++ ](i) caused a significant decrease in 15/7 binding and adhesion stimulated by low (1 ng/ml) concentrations of phorbol myristate acetate (PMA). The inhibitory effect of [Ca ++ ](i) chelation on β1 integrin activation was reversed by repleting [Ca ++ ](i) with ionomycin in a Ca ++ -containing buffer, or by the addition of higher concentrations of PMA (10 ng/ml). These data suggest a role for [Ca ++ ](i) in inside-out activation of pi integrins, probably through a synergistic effect with PKC activation.",
author = "Mark Rowin and Whatley, {Ralph E.} and Ted Yednock and Bohnsack, {John F.}",
year = "1998",
month = "5",
day = "1",
doi = "10.1002/(SICI)1097-4652(199805)175:2<193::AID-JCP9>3.0.CO;2-J",
language = "English (US)",
volume = "175",
pages = "193--202",
journal = "Journal of Cellular Physiology",
issn = "0021-9541",
publisher = "Wiley-Liss Inc.",
number = "2",

}

TY - JOUR

T1 - Intracellular calcium requirements for β1 integrin activation

AU - Rowin, Mark

AU - Whatley, Ralph E.

AU - Yednock, Ted

AU - Bohnsack, John F.

PY - 1998/5/1

Y1 - 1998/5/1

N2 - Human polymorphonuclear leukocytes (PMNs) express β1 integrins that mediate adhesion to extracellular matrix proteins following stimulation with agonists that induce an increase in intracellular calcium. The purpose of these studies was to determine the contribution made by alterations in intracellular calcium ([Ca ++ ](i)) to inside-out activation of pi integrins using dimethyl sulfoxide (DMSO)-differentiated granulocytic HL60 cells as a model of human PMNs. Activation of β1 integrins was determined by measuring the expression of an activation-dependent epitope on the β1 subunit that is recognized by monoclonal antibody (mAb) 15/ 7. Exposure of granulocytic HL60 cells to calcium ionophore ionomycin (800 nM) alone did not increase the binding of mAb 15/7 to the cell surface, nor did it increase β1 integrin-mediated adhesion of the cells to fibronectin. Similarly, exposure of the cells to the direct protein kinase C (PKC) activator, dioclanoylglycerol (di-C 8 ) at 100 μM, neither increased binding of mAb 15/7 to these cells nor adhesion to fibronectin. Simultaneous addition of di-C 8 and ionomycin, however, caused a significant increase in the expression of the 15/7 epitope and cell adhesion, suggesting synergy between elevating [Ca ++ ](i) and stimulating PKC in β1 integrin activation. Chelation of [Ca ++ ]((i)) with Quin-2 and EGTA reduced both basal (unstimulated) expression of the 15/7 epitope and basal adhesion of granulocytic HL60 cells to fibronectin. In addition, chelation of [Ca ++ ](i) caused a significant decrease in 15/7 binding and adhesion stimulated by low (1 ng/ml) concentrations of phorbol myristate acetate (PMA). The inhibitory effect of [Ca ++ ](i) chelation on β1 integrin activation was reversed by repleting [Ca ++ ](i) with ionomycin in a Ca ++ -containing buffer, or by the addition of higher concentrations of PMA (10 ng/ml). These data suggest a role for [Ca ++ ](i) in inside-out activation of pi integrins, probably through a synergistic effect with PKC activation.

AB - Human polymorphonuclear leukocytes (PMNs) express β1 integrins that mediate adhesion to extracellular matrix proteins following stimulation with agonists that induce an increase in intracellular calcium. The purpose of these studies was to determine the contribution made by alterations in intracellular calcium ([Ca ++ ](i)) to inside-out activation of pi integrins using dimethyl sulfoxide (DMSO)-differentiated granulocytic HL60 cells as a model of human PMNs. Activation of β1 integrins was determined by measuring the expression of an activation-dependent epitope on the β1 subunit that is recognized by monoclonal antibody (mAb) 15/ 7. Exposure of granulocytic HL60 cells to calcium ionophore ionomycin (800 nM) alone did not increase the binding of mAb 15/7 to the cell surface, nor did it increase β1 integrin-mediated adhesion of the cells to fibronectin. Similarly, exposure of the cells to the direct protein kinase C (PKC) activator, dioclanoylglycerol (di-C 8 ) at 100 μM, neither increased binding of mAb 15/7 to these cells nor adhesion to fibronectin. Simultaneous addition of di-C 8 and ionomycin, however, caused a significant increase in the expression of the 15/7 epitope and cell adhesion, suggesting synergy between elevating [Ca ++ ](i) and stimulating PKC in β1 integrin activation. Chelation of [Ca ++ ]((i)) with Quin-2 and EGTA reduced both basal (unstimulated) expression of the 15/7 epitope and basal adhesion of granulocytic HL60 cells to fibronectin. In addition, chelation of [Ca ++ ](i) caused a significant decrease in 15/7 binding and adhesion stimulated by low (1 ng/ml) concentrations of phorbol myristate acetate (PMA). The inhibitory effect of [Ca ++ ](i) chelation on β1 integrin activation was reversed by repleting [Ca ++ ](i) with ionomycin in a Ca ++ -containing buffer, or by the addition of higher concentrations of PMA (10 ng/ml). These data suggest a role for [Ca ++ ](i) in inside-out activation of pi integrins, probably through a synergistic effect with PKC activation.

UR - http://www.scopus.com/inward/record.url?scp=0031887880&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0031887880&partnerID=8YFLogxK

U2 - 10.1002/(SICI)1097-4652(199805)175:2<193::AID-JCP9>3.0.CO;2-J

DO - 10.1002/(SICI)1097-4652(199805)175:2<193::AID-JCP9>3.0.CO;2-J

M3 - Article

VL - 175

SP - 193

EP - 202

JO - Journal of Cellular Physiology

JF - Journal of Cellular Physiology

SN - 0021-9541

IS - 2

ER -