Identification of transcripts overexpressed during airway epithelium differentiation

¹ Laboratoire Cardiogénétique, EA 4171, Université Lyon 1, Lyon, France; and Laboratoire Cardiogénétique, ERM 0107, INSERM, Lyon, France
² Laboratoire de Parasitologie, Université Lyon 1, Lyon, France
³ Service ORL, Hôpital de la Croix-Rousse, Hospices Civils de Lyon, Lyon, France
⁴ Laboratoire Cardiogénétique, EA 4171, Université Lyon 1, Lyon, France; Laboratoire Cardiogénétique, ERM 0107, INSERM, Lyon, France; and Laboratoire Cardiogénétique, CBPE, Groupe Hospitalier Est, Hospices Civils de Lyon, Lyon, France

^* To whom correspondence should be addressed. E-mail: Patrice.Bouvagnet{at}recherche.univ-lyon1.fr.

	Abstract

Human airway epithelium, the forefront defence protecting the respiratory tract, evacuates inhaled particles by a permanent beating of epithelial cells cilia. When deficient, this organelle causes Primary Ciliary Dyskinesia (PCD), and despite numerous studies, data regarding ciliated cells gene expression are still incomplete. To identify genes specifically expressed in human ciliated respiratory cells, we performed a transcriptional analysis.

The transcriptome of de-differentiated epithelial cells was subtracted from fully re-differentiated cells using cDNA Representational Difference Analysis (RDA). To validate our results, gene overexpression in ciliated cells was confirmed by real-time PCR (RT-PCR), and by comparing our list of ciliated cell overexpressed genes to list obtained in previous studies.

We identified 53 known and 12 unknown genes overexpressed in ciliated cells. A majority (66%) of known genes was never reported before as being involved in ciliogenesis, while unknown genes represent hypothetical novel transcript isoforms or new genes not yet reported in databases. Finally, several genes identified here were located in genomic regions involved in PCD by linkage analysis.

In conclusion, this study revealed sequences of new cilia-related genes, new transcript isoforms and novel genes which should be further characterized for an understanding of their function(s) and their probable disorder-related involvement.