title: Decreased expression of surfactant protein genes is associated with an increased expression of Forkhead box M1 gene in the fetal lung tissues of premature rabbits.
abstract: OBJECTIVE
  Recently, Forkhead box M1 (FoxM1) was reported to be correlated with lung maturation and expression of surfactant proteins (SPs) in mice models. However, no study has been conducted in rabbit lungs despite their high homology with human lungs. Thus, we attempted to investigate serial changes in the expressions of FoxM1 and SP-A/B throughout lung maturation in rabbit fetuses.
  
  
  METHODS
  Pregnant New Zealand White rabbits were grouped according to gestational age from 5 days before to 2 days after the day of expected full term delivery (F5, F4, F3, F2, F1, F0, P1, and P2). A total of 64 fetuses were enrolled after Cesarean sections. The expressions of mRNA and proteins of FoxM1 and SP-A/B in fetal lung tissue were tested by quantitative reverse-transcriptase real-time PCR and Western blot. Furthermore, their correlations were analyzed.
  
  
  RESULTS
  The mRNA expression of SP-A/B showed an increasing tendency positively correlated with gestational age, while the expression of FoxM1 mRNA and protein decreased from F5 to F0. A significant negative correlation was found between the expression levels of FoxM1 and SP-A/B (SP-A: R=-0.517, p=0.001; SP-B: R=-0.615, p<0.001).
  
  
  CONCLUSIONS
  Preterm rabbits demonstrated high expression of FoxM1 mRNA and protein in the lungs compared to full term rabbits. Also, the expression of SP-A/B was inversely related with serial changes in FoxM1 expression. This is the first report to suggest an association between FoxM1 and expression of SP-A/B and lung maturation in preterm rabbits.
authors.affiliation: Department of Pediatrics, Kyung Hee University Hospital at Gangdong, 892 Dongnam-ro, Gangdong-gu, Seoul 134-727, Korea. baecw@khnmc.or.kr.
authors.forename: Won-Ho
authors.initials: WH
authors.lastname: Hahn
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Chang
authors.forename: Kyung Suk
authors.initials: KS
authors.lastname: Lee
authors.forename: Chong-Woo
authors.initials: CW
authors.lastname: Bae
mesh_terms: D000818:Animals; D015153:Blotting, Western; D005260:Female; D005333:Fetus / Q000378:metabolism*; D051858:Forkhead Transcription Factors / Q000378:metabolism*; D008168:Lung / Q000378:metabolism*; D011247:Pregnancy; D037662:Pulmonary Surfactant-Associated Protein A / Q000235:genetics / Q000378:metabolism*; D011817:Rabbits
chemical_list: D051858:Forkhead Transcription Factors; D037662:Pulmonary Surfactant-Associated Protein A
keywords: FoxM1; mRNA; prematurity; protein; surfactant protein-A; surfactant protein-B