Epimorphin expression in a rat model of pulmonary hypoplasia associated with congenital diaphragmatic hernia.

[congenital diaphragmatic hernia]

The pathogenesis of pulmonary hypoplasia associated with congenital diaphragmatic hernia (CDH ) remains unclear . Interactions between the epithelium and surrounding mesenchyme play an important role in normal lung morphogenesis . Epimorphin , a stromal protein , plays a role in epithelial morphogenesis and lung branching , both of which are involved in pulmonary hypoplasia . In this study , we aimed to examine the relationship between epimorphin and pulmonary hypoplasia associated with CDH in an animal model .Time-pregnant rats were exposed to nitrofen or vehicle on gestational day 9 (D 9 ). Fetuses were harvested on D 16 and D 20 , and were divided into control , hypoplastic lungs with CDH (CDH +), and hypoplastic lungs without CDH (CDH -). Both lungs of each fetus were removed and subjected to morphometric and molecular biologic analyses . Lung -to -body weight ratios were calculated . Pulmonary RNA was extracted , and relative mRNA level of epimorphin was determined by quantitative real-time PCR (qRT-PCR ). Protein expression of epimorphin was investigated by Western blotting .In groups D 16 and D 20 , lung -to -body weight ratios in subgroups CDH + were significantly lower than those of controls and CDH -. The relative mRNA expression levels of epimorphin were significantly increased in both lungs in subgroup CDH + compared with controls and CDH - on D 16 . Pulmonary epimorphin gene expression levels were significantly decreased in CDH + group on D 20 compared to controls . Western blotting confirmed the qRT-PCR results showing decreased pulmonary epimorphin protein expression in CDH + hypoplastic lungs compared to controls on D 20 .O ur study shows that there is an association between the epimorphin expression and pulmonary hypoplasia associated with CDH . Although the cause-effect relationship is far from being established , epimorphin-related mechanisms have a more critical role in early (D 16 ) developmental stage .