Identification of Genes Differentially Expressed in Rat Alveolar Type I Cells

• DOI: 10.1165/rcmb.2003-0423oc
• Publication Date: 2004-06-18T00:34:24Z
• Authors: Katherine Dahlin; Edward M. Mager; Lennell Allen; Zachary Tigue; Lee Goodglick; Madhuri Wadehra; Leland Dobbs
• Keywords: Tissue Inhibitor of Metalloproteinase-3; 0303 health sciences; Membrane Glycoproteins; Gene Expression Profiling; Caveolin 1; Endothelial Cells; Membrane Proteins; Nerve Tissue Proteins; Caveolins; Rats; Pulmonary Alveoli; Rats, Sprague-Dawley; 03 medical and health sciences; Gene Expression Regulation; Animals; RNA, Messenger

Although approximately 98% of the internal surface area of the lung is lined by alveolar type I cells, little is known about the functions of this cell type. Using freshly isolated rat type I and type II cells, we created a subtraction library by suppression subtractive hybridization to identify genes differentially expressed by type I cells. We identified twelve genes of known function that are differentially expressed by type I cells. Differential expression of all 12 genes was confirmed by Northern blotting; we confirmed differential expression by immunocytochemistry for 3 genes for which suitable antibodies were available. Most of the genes code for proteins that are multifunctional. From the known functions of these genes, we infer that type I cells may play a role in the maintenance of normal alveolar homeostasis and protection from injury, lung development and remodeling, host defense, tumor/growth suppression, and surfactant metabolism, among other functions.