Zinc modulates cytokine-induced lung epithelial cell barrier permeability

Shenying Bao, Daren L. Knoell

Research output: Contribution to journalArticle

39 Citations (Scopus)

Abstract

Apoptosis plays a causative role in acute lung injury in part due to epithelial cell loss. We recently reported that zinc protects the lung epithelium during inflammatory stress whereas depletion of intracellular zinc enhances extrinsic apoptosis. In this investigation, we evaluated the relationship between zinc, caspase-3, and cell-to-cell contact via proteins that form the adherens junction complex. Cell adhesion proteins are directly responsible for formation of the mechanical barrier of the lung epithelium. We hypothesized that exposure to inflammatory cytokines, in conjunction with zinc deprivation, would induce caspase-3, leading to degradation of junction proteins, loss of cell-to-cell contact, and compromised barrier function. Primary human upper airway and type I/II alveolar epithelial cultures were obtained from multiple donors and exposed to inflammatory stimuli that provoke extrinsic apoptosis in addition to depletion of intracellular zinc. We observed that zinc deprivation combined with tumor necrosis factor-α, interferon-γ, and Fas receptor ligation accelerates caspase-3 activation, proteolysis of E-cadherin and β-catenin, and cellular apoptosis, leading to increased paracellular leak across monolayers of both upper airway and alveolar lung epithelial cultures. Zinc supplementation inhibited apoptosis and paracellular leak, whereas caspase inhibition was less effective. We conclude that zinc is a vital factor in the lung epithelium that protects against death receptor-mediated apoptosis and barrier dysfunction. Furthermore, our findings suggest that although caspase-3 inhibition reduces lung epithelial apoptosis it does not prevent mechanical dysfunction. These findings facilitate future studies aimed at developing therapeutic strategies to prevent acute lung injury.

Original languageEnglish (US)
Pages (from-to)L1132-L1141
JournalAmerican Journal of Physiology - Lung Cellular and Molecular Physiology
Volume291
Issue number6
DOIs
StatePublished - Dec 1 2006

Fingerprint

Zinc
Permeability
Epithelial Cells
Cytokines
Lung
Apoptosis
Caspase 3
Epithelium
Acute Lung Injury
Proteolysis
Interferon Receptors
CD95 Antigens
Adherens Junctions
Catenins
Death Domain Receptors
Tumor Necrosis Factor Receptors
Cadherins
Caspases
Cell Adhesion
Ligation

Keywords

  • Adherens junction
  • Barrier dysfunction
  • Caspase
  • Lung epithelium
  • Programmed cell death

ASJC Scopus subject areas

  • Physiology
  • Pulmonary and Respiratory Medicine
  • Physiology (medical)
  • Cell Biology

Cite this

Zinc modulates cytokine-induced lung epithelial cell barrier permeability. / Bao, Shenying; Knoell, Daren L.

In: American Journal of Physiology - Lung Cellular and Molecular Physiology, Vol. 291, No. 6, 01.12.2006, p. L1132-L1141.

Research output: Contribution to journalArticle

@article{f0968d2a501745ecb06289f1d82ff4c0,
title = "Zinc modulates cytokine-induced lung epithelial cell barrier permeability",
abstract = "Apoptosis plays a causative role in acute lung injury in part due to epithelial cell loss. We recently reported that zinc protects the lung epithelium during inflammatory stress whereas depletion of intracellular zinc enhances extrinsic apoptosis. In this investigation, we evaluated the relationship between zinc, caspase-3, and cell-to-cell contact via proteins that form the adherens junction complex. Cell adhesion proteins are directly responsible for formation of the mechanical barrier of the lung epithelium. We hypothesized that exposure to inflammatory cytokines, in conjunction with zinc deprivation, would induce caspase-3, leading to degradation of junction proteins, loss of cell-to-cell contact, and compromised barrier function. Primary human upper airway and type I/II alveolar epithelial cultures were obtained from multiple donors and exposed to inflammatory stimuli that provoke extrinsic apoptosis in addition to depletion of intracellular zinc. We observed that zinc deprivation combined with tumor necrosis factor-α, interferon-γ, and Fas receptor ligation accelerates caspase-3 activation, proteolysis of E-cadherin and β-catenin, and cellular apoptosis, leading to increased paracellular leak across monolayers of both upper airway and alveolar lung epithelial cultures. Zinc supplementation inhibited apoptosis and paracellular leak, whereas caspase inhibition was less effective. We conclude that zinc is a vital factor in the lung epithelium that protects against death receptor-mediated apoptosis and barrier dysfunction. Furthermore, our findings suggest that although caspase-3 inhibition reduces lung epithelial apoptosis it does not prevent mechanical dysfunction. These findings facilitate future studies aimed at developing therapeutic strategies to prevent acute lung injury.",
keywords = "Adherens junction, Barrier dysfunction, Caspase, Lung epithelium, Programmed cell death",
author = "Shenying Bao and Knoell, {Daren L.}",
year = "2006",
month = "12",
day = "1",
doi = "10.1152/ajplung.00207.2006",
language = "English (US)",
volume = "291",
pages = "L1132--L1141",
journal = "American Journal of Physiology - Renal Physiology",
issn = "0363-6127",
publisher = "American Physiological Society",
number = "6",

}

TY - JOUR

T1 - Zinc modulates cytokine-induced lung epithelial cell barrier permeability

AU - Bao, Shenying

AU - Knoell, Daren L.

PY - 2006/12/1

Y1 - 2006/12/1

N2 - Apoptosis plays a causative role in acute lung injury in part due to epithelial cell loss. We recently reported that zinc protects the lung epithelium during inflammatory stress whereas depletion of intracellular zinc enhances extrinsic apoptosis. In this investigation, we evaluated the relationship between zinc, caspase-3, and cell-to-cell contact via proteins that form the adherens junction complex. Cell adhesion proteins are directly responsible for formation of the mechanical barrier of the lung epithelium. We hypothesized that exposure to inflammatory cytokines, in conjunction with zinc deprivation, would induce caspase-3, leading to degradation of junction proteins, loss of cell-to-cell contact, and compromised barrier function. Primary human upper airway and type I/II alveolar epithelial cultures were obtained from multiple donors and exposed to inflammatory stimuli that provoke extrinsic apoptosis in addition to depletion of intracellular zinc. We observed that zinc deprivation combined with tumor necrosis factor-α, interferon-γ, and Fas receptor ligation accelerates caspase-3 activation, proteolysis of E-cadherin and β-catenin, and cellular apoptosis, leading to increased paracellular leak across monolayers of both upper airway and alveolar lung epithelial cultures. Zinc supplementation inhibited apoptosis and paracellular leak, whereas caspase inhibition was less effective. We conclude that zinc is a vital factor in the lung epithelium that protects against death receptor-mediated apoptosis and barrier dysfunction. Furthermore, our findings suggest that although caspase-3 inhibition reduces lung epithelial apoptosis it does not prevent mechanical dysfunction. These findings facilitate future studies aimed at developing therapeutic strategies to prevent acute lung injury.

AB - Apoptosis plays a causative role in acute lung injury in part due to epithelial cell loss. We recently reported that zinc protects the lung epithelium during inflammatory stress whereas depletion of intracellular zinc enhances extrinsic apoptosis. In this investigation, we evaluated the relationship between zinc, caspase-3, and cell-to-cell contact via proteins that form the adherens junction complex. Cell adhesion proteins are directly responsible for formation of the mechanical barrier of the lung epithelium. We hypothesized that exposure to inflammatory cytokines, in conjunction with zinc deprivation, would induce caspase-3, leading to degradation of junction proteins, loss of cell-to-cell contact, and compromised barrier function. Primary human upper airway and type I/II alveolar epithelial cultures were obtained from multiple donors and exposed to inflammatory stimuli that provoke extrinsic apoptosis in addition to depletion of intracellular zinc. We observed that zinc deprivation combined with tumor necrosis factor-α, interferon-γ, and Fas receptor ligation accelerates caspase-3 activation, proteolysis of E-cadherin and β-catenin, and cellular apoptosis, leading to increased paracellular leak across monolayers of both upper airway and alveolar lung epithelial cultures. Zinc supplementation inhibited apoptosis and paracellular leak, whereas caspase inhibition was less effective. We conclude that zinc is a vital factor in the lung epithelium that protects against death receptor-mediated apoptosis and barrier dysfunction. Furthermore, our findings suggest that although caspase-3 inhibition reduces lung epithelial apoptosis it does not prevent mechanical dysfunction. These findings facilitate future studies aimed at developing therapeutic strategies to prevent acute lung injury.

KW - Adherens junction

KW - Barrier dysfunction

KW - Caspase

KW - Lung epithelium

KW - Programmed cell death

UR - http://www.scopus.com/inward/record.url?scp=33845415089&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33845415089&partnerID=8YFLogxK

U2 - 10.1152/ajplung.00207.2006

DO - 10.1152/ajplung.00207.2006

M3 - Article

C2 - 16844947

AN - SCOPUS:33845415089

VL - 291

SP - L1132-L1141

JO - American Journal of Physiology - Renal Physiology

JF - American Journal of Physiology - Renal Physiology

SN - 0363-6127

IS - 6

ER -