Pro-inflammatory effects of extracellular Hsp70 on NCI-H292 human bronchial epithelial cell line

Int J Exp Pathol. 2019 Oct;100(5-6):320-329. doi: 10.1111/iep.12335. Epub 2019 Dec 11.

Abstract

Extracellular Hsp70 (eHsp70) exerts its biological actions via Toll-like receptors 2 and 4, and is increased in sera of chronic obstructive pulmonary disease (COPD) patients. The aim of this study was to explore the pro-inflammatory effects and cytotoxicity of eHsp70 alone and in combination with bacterial components lipoteichoic acid (LTA) and lipopolysaccharide (LPS) on NCI-H292 airway epithelial cells. NCI-H292 cells were treated with recombinant human Hsp70 protein (rhHsp70), LPS, LTA and their combinations for 4, 12, 24 and 48 hours. IL-6, IL-8 and TNF-α levels were measured by an ELISA method. Cell viability was determined by the MTS method, and caspase-3/7, caspase-8 and caspase-9 assays. rhHsp70 induced secretion of IL-6 and IL-8 in a concentration- and time-dependent manner, with the highest secretion at 24 hours. rhHsp70 combined with LTA had antagonistic and with LPS synergistic effect on IL-6 secretion, while the interactions between rhHsp70 and LPS or LTA on IL-8 were synergistic. TNF-α was not detected in the applied conditions. rhHsp70, LPS or LTA did not affect cell viability, and rhHsp70 even suppressed caspase-3/7 activities. We suggest that pro-inflammatory effects of eHsp70, together with other damaging molecules and/or COPD risk factors, might contribute to the aggravation of chronic inflammation in human bronchial epithelium.

Keywords: COPD; LPS; LTA; NCI-H292 cells; extracellular Hsp70.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomarkers / metabolism
  • Cell Line
  • Cell Survival
  • Cytokines / metabolism
  • Enzyme-Linked Immunosorbent Assay
  • Epithelial Cells / metabolism*
  • HSP70 Heat-Shock Proteins / metabolism*
  • Humans
  • Inflammation / metabolism*
  • Pulmonary Disease, Chronic Obstructive / metabolism*
  • Respiratory Mucosa / metabolism*

Substances

  • Biomarkers
  • Cytokines
  • HSP70 Heat-Shock Proteins