Chronological expression of Ciliated Bronchial Epithelium 1 during pulmonary development

¹ Infection, Inflammation and Repair Division
² Infection, Inflammation and Repair Division; and Human Anatomy Section, University of Palermo, Palermo, Italy
³ Infection, Inflammation and Repair Division; and Centre for Human Development, Stem Cells and Regeneration, Human Genetics Division, School of Medicine, University of Southampton, Southampton General Hospital, Southampton, United Kingdom
⁴ Centre for Human Development, Stem Cells and Regeneration, Human Genetics Division, School of Medicine, University of Southampton, Southampton General Hospital, Southampton, United Kingdom
⁵ Human Anatomy Section, University of Palermo, Palermo, Italy

^* To whom correspondence should be addressed. E-mail: E-mail:donnad{at}soton.ac.uk.

	Abstract

Ciliated Bronchial Epithelium (CBE) 1 is a novel gene, expressed in ciliated cells. As cilia are important during embryogenesis, we have characterized the murine homologue of CBE1 (Cbe1) and compared its temporal expression during murine and human lung development.

Cbe1 cDNA was cloned and characterised using sequencing, standard PCR and Western blotting. Mouse and human embryonic/foetal lungs (HELs) were harvested for mRNA analysis and protein localisation in vivo and in vitro using RT-PCR and immunohistochemistry.

Cbe1 amino acid sequence was >75% identical with CBE1 and its alternative splicing and tissue distribution were highly conserved. Pulmonary expression of Cbe1 mRNA was increased at embryonic day 16 (E16), one day later than Foxj1, consistent with a role in ciliogenesis. In HELs, CBE1 mRNA was detectable at 8–9 weeks post conception and increased in explant culture. CBE1 protein expression was weak at 10 weeks post conception but strong at 12.3 weeks post conception, in parallel with cilia formation. Additionally, Cbe1 mRNA was expressed at E11 (4–5 weeks post conception in HELs) in the absence of Foxj1, implying a distinct role in early development.

Chronological regulation of CBE1/Cbe1 expression during pulmonary differentiation suggests involvement in ciliogenesis, with an additional role during early lung development.