title: Studies of intestinal morphology and cathepsin B expression in a transgenic mouse aiming at intestine-specific expression of Cath B-EGFP.
abstract: Cathepsin B has been shown to not only reside within endo-lysosomes of intestinal epithelial cells, but it was also secreted into the extracellular space of intestinal mucosa in physiological and pathological conditions. In an effort to further investigate the function of this protease in the intestine, we generated a transgenic mouse model that would enable us to visualize the localization of cathepsin B in vivo. Previously we showed that the A33-antigen promoter could be successfully used in vitro in order to express cathepsin B-green fluorescent protein chimeras in cells that co-expressed the intestine-specific transcription factor Cdx1. In this study an analog approach was used to express chimeric cathepsin B specifically in the intestine of transgenic animals. No overt phenotype was observed for the transgenic mice that reproduced normally. Biochemical and morphological studies confirmed that the overall intestinal phenotype including the structure and polarity of this tissue as well as cell numbers and differentiation states were not altered in the A33-CathB-EGFP mice when compared to wild type animals. However, transgenic expression of chimeric cathepsin B could not be visualized because it was not translated in situ although the transgene was maintained over several generations.
authors.affiliation: School of Engineering and Science, Research Center MOLIFE - Molecular Life Science, Jacobs University Bremen, Campus Ring 6, D-28759 Bremen, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Arampatzidou
authors.forename: Kristina
authors.initials: K
authors.lastname: Mayer
authors.forename: Maria E
authors.initials: ME
authors.lastname: Iolyeva
authors.forename: Seblewongel Gebre
authors.initials: SG
authors.lastname: Asrat
authors.forename: Mirunalini
authors.initials: M
authors.lastname: Ravichandran
authors.forename: Thomas
authors.initials: T
authors.lastname: Günther
authors.forename: Roland
authors.initials: R
authors.lastname: Schüle
authors.forename: Thomas
authors.initials: T
authors.lastname: Reinheckel
authors.forename: Klaudia
authors.initials: K
authors.lastname: Brix
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002401:Cathepsin B / Q000032:analysis / Q000235:genetics*; D015870:Gene Expression; D049452:Green Fluorescent Proteins / Q000235:genetics; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000648:ultrastructure; D008562:Membrane Glycoproteins / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D019076:Transgenes
chemical_list: C504395:Gpa33 protein, mouse; D008562:Membrane Glycoproteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D002401:Cathepsin B