TNF-α increases Staphylococcus aureus-induced death of human alveolar epithelial cell line A549 associated with RIP3-mediated necroptosis.

Abstract

AIM:

To explore the role of tumor necrosis factor-alpha (TNF-α) on Staphylococcus aureus-induced necroptosis in alveolar epithelial cells.

MAIN METHODS:

The A549 alveolar epithelial cell line was pretreated with small interfering RNA (siRNA) against receptor interacting protein-3 (RIP3) and then stimulated by S. aureus, where some cells were pretreated with TNF-α or TNF-α with anti-TNF-α antibody simultaneously. A549 cell death was assessed using lactate dehydrogenase (LDH) leakage and flow cytometry analyses. The protein expressions of RIP1, RIP3, cleaved caspase-1, and cleaved caspase-8 were analyzed by western blot.

KEY FINDINGS:

S. aureus-induced LDH release was increased significantly by TNF-α. In addition, flow cytometry showed that TNF-α increased A549 cell apoptosis and necrosis in S. aureus-infected cell cultures. Levels of RIP3 and cleaved caspase-1 protein in A549 cells infected with S. aureus increased at 12 h post-infection, as shown by western blot. Significant additional increases in RIP3 expression were observed following the addition of TNF-α. Decreasing RIP3 levels by siRNA significantly suppressed the release of LDH induced by TNF-α and S. aureus. RIP3 siRNA also significantly suppressed A549 cell necrosis induced by S. aureus and TNF-α at 6 and 12 h post-infection as shown by flow cytometry analysis.

SIGNIFICANCE:

TNF-α enhances the damage of S. aureus on lung epithelial cells, and its mechanism is associated with RIP3 mediated necroptosis.

• Authors: Shun-Hang Wen, Luo-Na Lin, Hu-Jun Wu, Lu Yu, Li Lin, Li-Li Zhu, Hai-Yan Li, Hai-Lin Zhang, Chang-Chong Li
• Journal: Life sciences (Life Sci) Vol. 195 Pg. 81-86 (Feb 15 2018) ISSN: 1879-0631 [Electronic] Netherlands
• PMID: 29330116 (Publication Type: Journal Article)
• Copyright: Copyright © 2018 Elsevier Inc. All rights reserved.

Chemical References

• AGFG1 protein, human
• Nuclear Pore Complex Proteins
• RNA-Binding Proteins
• Tumor Necrosis Factor-alpha
• L-Lactate Dehydrogenase
• RIPK3 protein, human
• Receptor-Interacting Protein Serine-Threonine Kinases
• CASP8 protein, human
• Caspase 8

Topics

• A549 Cells
• Alveolar Epithelial Cells
• Caspase 8 (genetics, metabolism)
• Cell Death (drug effects)
• Humans
• L-Lactate Dehydrogenase (metabolism)
• Necrosis (chemically induced, pathology)
• Nuclear Pore Complex Proteins (drug effects, physiology)
• RNA-Binding Proteins (drug effects, physiology)
• Receptor-Interacting Protein Serine-Threonine Kinases (drug effects, physiology)
• Staphylococcus aureus (drug effects)
• Tumor Necrosis Factor-alpha (pharmacology)