[Effects of cyclic stretch on expression of cytokines and intercellular adhesion molecule-1 in human pulmonary artery...

To observe the effects of cyclic stretch on expression of cytokines and adhesion molecules in human pulmonary artery endothelial cells (HPAECs), herein to provide a theoretical basis to ventilator-induced lung injury (VILI).

HPAECs were subjected to cyclic stretch by the Flexcell FX-5000T system at 0.5 Hz of 10% or 20% elongation for 3, 6, 12, 24 hours respectively. The mRNA and protein expression of interleukin (IL-6, IL-8), monocyte chemotactic protein-1 (MCP-1) and intercellular adhesion molecule-1 (ICAM-1) was determined by fluorescent quantitation reverse transcription-polymerase chain reaction (qRT-PCR), enzyme linked immunosorbent assay (ELISA) or Western blotting.

Increasing the stretch force, the mRNA and protein expression of IL-8, MCP-1, ICAM-1 were up regulated with increasing stretch time. Compared with the control (set 1), after 20% cyclic stretch for 24 hours, IL-8 mRNA expression was up regulated to 1.58±0.10, MCP-1 mRNA expression was up regulated to 2.85±0.52, and ICAM-1 mRNA expression was up regulated to 1.90±0.14 (all P<0.05). Compared with control group, after 20% cyclic stretch for 24 hours, the protein expression of IL-8 and MCP-1 in HPAEC was significantly increased (IL-8: 3401.08±439.60 ng/L vs. 1422.60±66.98 ng/L, MCP-1: 1117.64±237.54 ng/L vs. 307.88±80.84 ng/L, both P<0.05), ICAM-1 protein expression was up regulated to 2.15±0.40 (P<0.05), while the expression of IL-6 mRNA and protein had no statistic difference compared with control group.

Cyclic stretch enhanced the expression of IL-8, MCP-1 and ICAM-1 in an intensity-dependent fashion, so it may be involved in the pathogenesis of lung injury induced by mechanical ventilation.