Fibronectin and its a5b1 integrin receptor are involved in the wound repair process of the airway epithelium. H[umlaut]arard, Anne-Laure, Denis Pierrot, Jocelyne Hinnrasky, Herv[umlaut]a Kaplan, Dean Sheppard, Edith Puchelle, and Jean-Marie Zahm. INSERM U314, Reims, France, 2Lung Biology Center, UCSF, San Francisco, USA
APStracts 3:0102L, 1996.
The cell migration which occurs during wound repair is dependent on modifications of the cell-matrix interaction, in which extracellular matrix proteins and their receptors, the integrins, are involved. In order to study the interactions between airway epithelial cells and the extracellular matrix during the process of wound repair, we developed an in vitro wound model of human epithelial cells. Surface epithelial cells were dissociated from human nasal polyps and cultured on a type I collagen matrix. At confluency, a wound was made by the addition of 2 ml of NaOH (1N) to the cell culture. After washing the cell culture, the wound area was recorded every 12 hours for 96 hours by a videomicroscopic technique. We calculated the wound repair index representing the decrease in the wound area per hour. Using immunofluorescence techniques, we firstly examined the localization, during wound repair, of fibronectin and of the b1, aV, a2, a3 and a5 integrin subunits. Secondly, we carried out a series of wound repair blocking experiments using anti-integrin or anti -fibronectin antibodies diluted in the culture medium. We observed that fibronectin and the a5 integrin subunit were exclusively expressed by the migratory cells in the wounded area. No difference in the localization of the aV, a2, a3 integrin subunits was observed between the non-repairing cells and the repairing cells. The blocking experiments showed a significant decrease in the wound repair index in the presence of either the anti-b1, anti-a3, anti-a5 or the anti -fibronectin antibodies. Furthermore, the addition of fbronectin and the corresponding a5b1 integrin play an important role in the process of airway epithelium wound repair.

Received 28 December 1995; accepted in final form 10 June 1996.
APS Manuscript Number L381-5.
Article publication pending Am. J. Physiol. (Lung Cell. Mol.
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 4 July 96