title: Protection against vascular leak in neprilysin transgenic mice with complex overexpression pattern.
abstract: Neprilysin (NEP) is a cell surface metallopeptidase found in many tissues. Based mostly on pharmacological manipulations, NEP has been thought to protect blood vessels from plasma extravasation. We have suggested that NEP may protect against pulmonary vascular injury. However, these prior studies did not utilize mice which overexpress NEP. The aims of the present investigation were to develop and characterize doubly transgenic (DT) mice that overexpress NEP universally and conditionally, and to investigate the protective effect that overexpressed NEP may have against plasma extravasation in the vasculature. The duodenum, which is often used to assess vascular permeability, and in which the NEP protein was overexpressed in our DT mice two-fold, was selected as our experimental preparation. We found that substance P-induced plasma extravasation was decreased substantially (3.5-fold) in the duodenums of our doxycycline-treated DT mice, giving independent evidence of NEP's protective effects against plasma extravasation. Transgenic lung NEP protein was not stably expressed in the DT mice, so we were not able to test the effect of NEP overexpression in the lung. Although initially overexpressed nearly nine-fold at that site, pulmonary NEP protein overexpression eventually dissipated. Surprisingly, at a time when there was no lung transgenic NEP protein overexpression, lung NEP mRNA expression was still increased 23-fold, indicating that the expression defect probably is not transcriptional. These studies help to characterize our complex transgenic model of NEP overexpression and further demonstrate NEP's protective effects against plasma extravasation.
authors.affiliation: Cardiovascular Pulmonary Research Laboratory, University of Colorado Denver, RC-2, Box B-133, 12700 E. 19th Ave., Aurora, CO, 80045, USA. Marilee.wick@ucdenver.edu.|Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Denver, Aurora, CO, 80045, USA. Marilee.wick@ucdenver.edu.
authors.forename: Marilee J
authors.initials: MJ
authors.lastname: Wick
authors.affiliation: Cardiovascular Pulmonary Research Laboratory, University of Colorado Denver, RC-2, Box B-133, 12700 E. 19th Ave., Aurora, CO, 80045, USA.|Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Denver, Aurora, CO, 80045, USA.
authors.forename: Zoe L
authors.initials: ZL
authors.lastname: Loomis
authors.affiliation: Cardiovascular Pulmonary Research Laboratory, University of Colorado Denver, RC-2, Box B-133, 12700 E. 19th Ave., Aurora, CO, 80045, USA.|Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Denver, Aurora, CO, 80045, USA.
authors.forename: Julie W
authors.initials: JW
authors.lastname: Harral
authors.affiliation: Denver VA Medical Center, Denver, CO, 80220, USA.
authors.forename: Mysan
authors.initials: M
authors.lastname: Le
authors.affiliation: Denver VA Medical Center, Denver, CO, 80220, USA.
authors.forename: Carol A
authors.initials: CA
authors.lastname: Wehling
authors.affiliation: Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Denver, Aurora, CO, 80045, USA.|Denver VA Medical Center, Denver, CO, 80220, USA.
authors.forename: York E
authors.initials: YE
authors.lastname: Miller
authors.affiliation: Cardiovascular Pulmonary Research Laboratory, University of Colorado Denver, RC-2, Box B-133, 12700 E. 19th Ave., Aurora, CO, 80045, USA.|Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Denver, Aurora, CO, 80045, USA.|Denver VA Medical Center, Denver, CO, 80220, USA.
authors.forename: Edward C
authors.initials: EC
authors.lastname: Dempsey
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000293:injuries / Q000378:metabolism* / Q000473:pathology; D004318:Doxycycline / Q000008:administration & dosage; D004386:Duodenum / Q000098:blood supply / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D008168:Lung / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D008822:Mice, Transgenic / Q000235:genetics / Q000378:metabolism; D015260:Neprilysin / Q000096:biosynthesis / Q000235:genetics*; D013373:Substance P / Q000378:metabolism
chemical_list: D013373:Substance P; D015260:Neprilysin; D004318:Doxycycline
keywords: Duodenum; Evans blue; Neprilysin; Rosa26 promoter; Transgenic mouse; Vascular leak