Gene expressions and roles of matrix metalloproteinases-8 and tissue inhibitor of metalloproteinases-1 in hyperoxia-induced pulmonary fibrosis in neonatal rats / 中国当代儿科杂志
Chinese Journal of Contemporary Pediatrics
;
(12): 1-5, 2007.
Article
in English
| WPRIM
| ID: wpr-357763
ABSTRACT
<p><b>OBJECTIVE</b>Extracellular matrix (ECM) deposition is a major reason of pulmonary fibrosis in hyperoxia-induced lung injury. However, the relevant mechanism has not been identified. This study examined the gene expressions of matrix metalloproteinases-8 (MMP-8, a catabolic enzyme of type I collagen) and tissue inhibitor of metalloproteinases-1 (TIMP-1) in neonatal rats with hyperoxia-induced pulmonary injury in order to explore the role of MMP-8 and TIMP-1 in pulmonary fibrosis.</p><p><b>METHODS</b>Eighty term newborn rats were randomly exposed to hyperoxia (FiO2=0.90, hyperoxia group)and to room air (FiO2=0.21, control group)(n=40 each). Lung injury was induced by hyperoxia exposure. The content of type I collagen and the expressions of type I collagen protein and MMP-1 mRNA and TIMP-1 mRNA were assayed with enzyme linked immunoadsorbent (ELISA), immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR) respectively on days 1, 3, 7, 14 and 21 after exposure.</p><p><b>RESULTS</b>The content of type I collagen and the expression of type I collagen protein in the hyperoxia group were statistically higher than those in the control group at 14 and 21 days post-exposure. The MMP-8 mRNA expression decreased while the TIMP-1 mRNA expression increased significantly in the hyperoxia group as compared to the control group at 14 and 21 days post-exposure.</p><p><b>CONCLUSIONS</b>Hyperoxia exposure down-regulates MMP-8 mRNA expression and up-regulates TIMP-1 mRNA expression. This results in a reduction of ECM degradation, thereby ECM deposition occurs in lung tissue, which may be an important mechanism of pulmonary fibrosis following hyperoxia-induced lung injury.</p>
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Physiology
/
Pulmonary Fibrosis
/
RNA, Messenger
/
Chronic Disease
/
Hyperoxia
/
Tissue Inhibitor of Metalloproteinase-1
/
Matrix Metalloproteinase 8
/
Collagen Type I
/
Genetics
/
Animals, Newborn
Limits:
Animals
Language:
English
Journal:
Chinese Journal of Contemporary Pediatrics
Year:
2007
Type:
Article
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