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There Is Binding of Collagen IV to β1 Integrin during Early Skin Basement Membrane Assembly
Author(s) -
FLEISCHMAJER RAUL,
PERLISH JEROME S.,
MACDONALD DOUGLAS E.,
SCHECHTER ALAN,
MURDOCH ALAN D.,
IOZZO RENATO V.,
YAMADA YOSHIHIKO
Publication year - 1998
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1111/j.1749-6632.1998.tb10118.x
Subject(s) - perlecan , lamina densa , basement membrane , integrin , chemistry , collagen receptor , microbiology and biotechnology , laminin , extracellular matrix , type iv collagen , receptor , biochemistry , biology , proteoglycan
This study is concerned with the mechanism of basement membrane assembly in an in vitro 3‐dimensional skin‐culture system. Dermal fibroblasts alone can synthesize collagen IV, perlecan, and nidogen, but cannot assemble them into a basement membrane. When keratinocytes are added to the culture, however, linear assembly of collagen IV, perlecan, and nidogen is noted at the epidermo‐dermal interface. Northern blots and in situ hybridization showed that perlecan and nidogen mRNAs derive exclusively from fibroblasts, while the α2 (IV) collagen chain is expressed by both keratinocytes and fibroblasts, although the major source is in the mesenchyma (80%). Prior to the development of the lamina densa, collagen IV colocalizes with α1 integrins, most likely α1β1 and α2β1, which are known receptors for this collagen. Blocking experiments with the AIIB2 mAb (anti‐β1 integrin subunit) and by peptide inhibition with the CB3(IV) collagen fragment disrupted the assembly of collagen IV. This study suggests that the initiation of basement‐membrane formation involves binding of collagen IV molecules to keratinocyte cell‐matrix integrins. These complexes act as nucleation sites for further polymerization of collagen IV molecules mostly derived from fibroblasts, by a process of self‐assembly.