2014 Ronde Kennisinfrastructuur (publiceren van negatieve of neutrale dierexperimentele data):
As part of an EU-funded FP7 collaborative project, we aimed to test the protective effects of PCDH1 overexpression on airway epithelial inegrity in mouse models of airway inflammation driven by house-duct mite and cigarette smoke exposure. To this end we generated PCDH1 conditional transgenic mice by inserting the human PCDH1 cDNA juxtaposed to a conditional STOP cassette into the ROSA26 locus. This transgene allows inducible expression of PCDH1 after a Cre mediated recombination event. To acjieve Cre expression in the airway epithelium, we used the SPC-rtTA/TetO-Cre bitransgenic strain that allows Doxycyclin inducible Cre expression in bronchial epithelial cells and alveolar epithelial cells. Analysis of the compound transgenic offspring revealed presence of germline recombination events in a fraction of the pups carrying the conditional transgene and the tet-operon responsive Cre transgene. Several breeding strategies were evaluated, but all failed to provide a low background of germline recombination events, and eventually this project was halted. We aim to publish these results in an open access journal since these effects of this widely used inducible Cre transgenic system have not been described in literature to date. After seeking information with some of our international collaborators, we learned of at least one other group that ran into similar problems. To avoid more research groups taking this same approach and running into similar problems, we aim to publish our findings.