Inhibition of matrix metalloproteinase-9 prevents neutrophilic inflammation in ventilator-induced lung injury

Je Hyeong Kim, Hyun Suk Min, Wui Yoon Dae, Seung Heon Lee, Gyu Young Hur, Hwan Jung Ki, Cheol Jeong Hae, Sung Yong Lee, Sang Yeub Lee, Bum Suh In, Chol Shin, Jae Jeong Shim, Kwang Ho In, Hwa Yoo Se, Kyung H. Kang

Research output: Contribution to journalArticle

88 Citations (Scopus)


Neutrophils are considered to play a central role in ventilator-induced lung injury (VILI). However, the pulmonary consequences of neutrophil accumulation have not been fully elucidated. Matrix metalloproteinase-9 (MMP-9) had been postulated to participate in neutrophil transmigration. The purpose of this study was to investigate the role of MMP-9 in the neutrophilic inflammation of VILI. Male Sprague-Dawley rats were divided into three groups: 1) low tidal volume (LVT), 7 ml/kg of tidal volume (VT); 2) high tidal volume (HVT), 30 ml/kg of VT; and 3) HVT with MMP inhibitor (HVT+MMPI). As a MMPI, CMT-3 was administered daily from 3 days before mechanical ventilation. Degree of VILI was assessed by wet-to-dry weight ratio and acute lung injury (ALI) scores. Neutrophilic inflammation was determined from the neutrophil count in the lung tissue and myeloperoxidase (MPO) activity in the bronchoalveolar lavage fluid (BALF). MMP-9 expression and activity were examined by immunohistochemical staining and gelatinase zymography, respectively. The wet-to-dry weight ratio, ALI score, neutrophil infiltration, and MPO activity were increased significantly in the HVT group. However, in the HVT+MMPI group, pretreatment with MMPI decreased significantly the degree of VILI, as well as neutrophil infiltration and MPO activity. These changes correlated significantly with MMP-9 immunoreactivity and MMP-9 activity. Most outcomes were significantly worse in the HVT+MMPI group compared with the LVT group. In conclusion, VILI mediated by neutrophilic inflammation is closely related to MMP-9 expression and activity. The inhibition of MMP-9 protects against the development of VILI through the downregulation of neutrophil-mediated inflammation.

Original languageEnglish
JournalAmerican Journal of Physiology - Lung Cellular and Molecular Physiology
Issue number4
Publication statusPublished - 2006 Oct 9



  • Mechanical ventilators
  • Metalloproteinase inhibitor
  • Neutrophil

ASJC Scopus subject areas

  • Cell Biology
  • Physiology
  • Pulmonary and Respiratory Medicine

Cite this