Cell culture models using rat primary alveolar type I cells

There is a lack of cell culture models using primary alveolar type I (AT I) cells. The purpose of this study was to develop cell culture models using rat AT I cells and microvascular endothelial cells from the lung (MVECL). Two types of model systems were developed: single and co-culture systems; additionally a 3-dimensional model system was developed. Pure AT I cell (96.3 +/- 2.7%) and MVECL (97.9 +/- 1.1%) preparations were used. AT I cell morphology, mitochondrial number and distribution, actin filament arrangement and number of apoptotic cells at confluence, and telomere attrition were characterized. All cells maintained their morphometric characteristics through at least population doubling (PD) 35, while demonstrating telomere attrition through at least PD 100. Furthermore, AT I cells maintained the expression of their specific markers, T1 alpha and AQ-5, through PD 42. For the co-cultures, AT I cells were grown on the top and MVECL were grown on the bottom of fibronectin-coated 24-well Transwell Fluroblok (TM) filter inserts. Neither cell type transmigrated the 1 mu m pores. Additionally, AT I cells were grown in a thick layer of Matrigel (R) to create a 3-dimensional model in which primary AT I cells form ring-like structures that resemble an alveolus. The development of these model systems offers the opportunities to investigate All cells and their interactions with MVECL in response to pharmacological interventions and in the processes of disease, repair and regeneration. (C) 2011 Elsevier Ltd. All rights reserved.