Recombinant osteopontin attenuates hyperoxia-induced acute lung injury through inhibiting nuclear factor kappa B and matrix metalloproteinases 2 and 9.
- Author:
Xiangfeng ZHANG
1
;
Fen LIU
2
;
Guangfa ZHU
3
;
Zengzhi WANG
3
Author Information
- Publication Type:Journal Article
- MeSH: Acute Lung Injury; genetics; metabolism; Animals; Hyperoxia; metabolism; physiopathology; Matrix Metalloproteinase 2; genetics; metabolism; Matrix Metalloproteinase 9; genetics; metabolism; Mice; NF-kappa B; genetics; metabolism; Osteopontin; genetics; metabolism; Tissue Inhibitor of Metalloproteinase-1; genetics; metabolism; Tissue Inhibitor of Metalloproteinase-2; genetics; metabolism
- From: Chinese Medical Journal 2014;127(23):4025-4030
- CountryChina
- Language:English
-
Abstract:
BACKGROUNDExposure of adult mice to more than 95% O2 produces a lethal injury by 72 hours. Nuclear factor kappa B (NF-κB) is a transcriptional factor that plays a key role in the modulation of cytokine networks during hyperoxia-induced acute lung injury (ALI). Osteopontin (OPN) is a phosphorylated glycoprotein produced principally by macrophages. Studies have reported that exogenous OPN can maintain the integrity of the cerebral microvascular basement membrane and reduce brain damage through inhibiting NF-κB activities in the brain after subarachnoid hemorrhage. However, it is not clear whether OPN can reduce lung injury during ALI by inhibiting transcriptional signal pathways of NF-κB and consequent inhibition of inflammatory cytokines. Thus we examined the effects and mechanisms of recombinant OPN (r-OPN) on ALI.
METHODSNinety-six mice were randomly divided into phosphate buffered saline (PBS) and r-OPN groups. Mice were put in an oxygen chamber (>95% O2) and assessed for lung injury at 24, 48, and 72 hours. Expressions of NF-κB, matrix metalloproteinases 2 and 9 (MMP-2 and MMP-9), and tissue inhibitors of MMP-2 and MMP-9 (TIMP-1, TIMP-2) mRNA in lungs were examined with RT-PCR. Expression and distribution of NF-κB protein in lungs were measured with immunohistochemistry.
RESULTSExposure to hyperoxia for 72 hours induced more severe lung injury in the PBS group compared with the r-OPN group. Expression of NF-κB mRNA in the PBS group exposed to hyperoxia for 48 and 72 hours was significantly higher than the r-OPN group (P < 0.05). With 72-hour exposure, expression of TIMP-1 mRNA in the r-OPN group was significantly higher than that of the PBS group (P < 0.05). Expression of TIMP-2 mRNA in the r-OPN group at 48 and 72 hours was significantly higher than those in the PBS group (P < 0.05). After 72-hour exposure, expression of NF-κB protein in airway epithelium in the PBS group was significantly higher than that in the r-OPN group (P < 0.05).
CONCLUSIONr-OPN can inhibit the release and activation of MMPs through inhibition of the expression of NF-κB and promotion of the expression of TIMPs, and alleviate hyperoxia-induced ALI.