Alveolocapillary model system to study alveolar re-epithelialization

Coen H. M. P. Willems, Luc J. I. Zimmermann, Patricia J. L. T. Sanders, Margot Wagendorp, Nico Kloosterboer, Jan Willem Cohen Tervaert, Hans J. Q. Duimel, Fons K. C. P. Verheyen, J. Freek van Iwaarden*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

In the present study an in vitro bilayer model system of the pulmonary alveolocapillary barrier was established to investigate the role of the microvascular endothelium on re-epithelialization. The model system, confluent monolayer cultures on opposing sides of a porous membrane, consisted of a human microvascular endothelial cell line (HPMEC-ST1.6R) and an alveolar type II like cell line (A549), stably expressing EGFP and mCherry, respectively. These fluorescent proteins allowed the real time assessment of the integrity of the monolayers and the automated analysis of the wound healing process after a scratch injury. The HPMECs significantly attenuated the speed of re-epithelialization, which was associated with the proximity to the A549 layer. Examination of cross-sectional transmission electron micrographs of the model system revealed protrusions through the membrane pores and close contact between the A549 cells and the HPMECs. Immunohistochemical analysis showed that these close contacts consisted of heterocellular gap-, tight- and adherens-junctions. Additional analysis, using a fluorescent probe to assess gap-junctional communication, revealed that the HPMECs and A549 cells were able to exchange the fluorophore, which could be abrogated by disrupting the gap junctions using connexin mimetic peptides. These data suggest that the pulmonary microvascular endothelium may impact the re-epithelialization process.
Original languageEnglish
Pages (from-to)64-74
JournalExperimental Cell Research
Volume319
Issue number1
DOIs
Publication statusPublished - 1 Jan 2013

Keywords

  • Pulmonary alveolus
  • Alveolocapillary model system
  • Co-culture
  • Re-epithelialization
  • Protrusions
  • Junctions
  • Communication
  • ATII
  • A549
  • Pulmonary microvascular endothelium
  • HPMEC

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