title: The alpha and beta subunits of the metalloprotease meprin are expressed in separate layers of human epidermis, revealing different functions in keratinocyte proliferation and differentiation.
abstract: The zinc endopeptidase meprin (EC 3.4.24.18) is expressed in brush border membranes of intestine and kidney tubules, intestinal leukocytes, and certain cancer cells, suggesting a role in epithelial differentiation and cell migration. Here we show by RT-PCR and immunoblotting that meprin is also expressed in human skin. As visualized by immunohistochemistry, the two meprin subunits are localized in separate cell layers of the human epidermis. Meprin alpha is expressed in the stratum basale, whereas meprin beta is found in cells of the stratum granulosum just beneath the stratum corneum. In hyperproliferative epidermis such as in psoriasis vulgaris, meprin alpha showed a marked shift of expression from the basal to the uppermost layers of the epidermis. The expression patterns suggest distinct functions for the two subunits in skin. This assumption is supported by diverse effects of recombinant meprin alpha and beta on human adult low-calcium high-temperature keratinocytes. Here, beta induced a dramatic change in cell morphology and reduced the cell number, indicating a function in terminal differentiation, whereas meprin alpha did not affect cell viability, and may play a role in basal keratinocyte proliferation.
authors.affiliation: Institute of Zoology, Johannes Gutenberg University, Johannes von Müller-Weg 6, Mainz, Germany. beckerpa@uni-mainz.de
authors.forename: Christoph
authors.initials: C
authors.lastname: Becker-Pauly
authors.forename: Markus
authors.initials: M
authors.lastname: Höwel
authors.forename: Tatjana
authors.initials: T
authors.lastname: Walker
authors.forename: Annica
authors.initials: A
authors.lastname: Vlad
authors.forename: Karin
authors.initials: K
authors.lastname: Aufenvenne
authors.forename: Vinzenz
authors.initials: V
authors.lastname: Oji
authors.forename: Daniel
authors.initials: D
authors.lastname: Lottaz
authors.forename: Erwin E
authors.initials: EE
authors.lastname: Sterchi
authors.forename: Mekdes
authors.initials: M
authors.lastname: Debela
authors.forename: Viktor
authors.initials: V
authors.lastname: Magdolen
authors.forename: Heiko
authors.initials: H
authors.lastname: Traupe
authors.forename: Walter
authors.initials: W
authors.lastname: Stöcker
mesh_terms: D002452:Cell Count; D002454:Cell Differentiation / Q000502:physiology*; D002460:Cell Line; D049109:Cell Proliferation; D002470:Cell Survival / Q000502:physiology; D000078404:Epidermal Cells; D004817:Epidermis / Q000502:physiology*; D005786:Gene Expression Regulation; D006801:Humans; D007610:Kallikreins / Q000502:physiology; D015603:Keratinocytes / Q000166:cytology / Q000502:physiology*; D008666:Metalloendopeptidases / Q000235:genetics / Q000502:physiology*
chemical_list: D007610:Kallikreins; C120801:kallikrein 4; D008666:Metalloendopeptidases; C053833:meprin A