AJP - Renal Physiology, Vol 261, Issue 4 688-F695, Copyright © 1991 by American Physiological Society
Adult and fetal human mesangial cells interact with specific laminin domains
B. S. Weeks, J. B. Kopp, S. Horikoshi, F. B. Cannon, M. Garrett, H. K. Kleinman and P. E. Klotman
Laboratory of Developmental Biology, National Institutes of Health, National Institute of Dental Research, Bethesda, Maryland 20892.
Mesangial cells are centrally located pericytes in the renal glomerulus.
They are surrounded by an extracellular matrix and directly contact the
glomerular basement membrane in vivo. Because these interactions are
critical for renal development and function, we have studied human
mesangial cell interactions with laminin, a major adhesive component of
basement membranes present in the extracellular matrix of the mesangium.
Human fetal and adult mesangial cell attachment was stimulated by both
laminin and the laminin-derived synthetic peptides YIGSR-NH2,
CQAGTFALRGDNPQG-NH2, and CIKVAVS-NH2. Furthermore, mesangial cells spread
on laminin as well as on both the RGD-containing and CIKVAVS peptides. When
added in solution, all three peptides inhibited mesangial cell attachment
to laminin, and the latter two peptides inhibited mesangial cell spreading
on laminin. Laminin affinity column chromatography demonstrated several
low-molecular-mass laminin-binding proteins ranging from between 35 and 42
kDa, which predominated in fetal mesangial cells, whereas a higher
molecular mass laminin-binding protein of 65 kDa was predominant in adult
mesangial cells. Western blot analysis with an anti-32-kDa laminin-binding
protein antibody showed increased expression of both 31- and 42-kDa
proteins in fetal mesangial cells when compared with the adult. The
antisera to the 32-kDa laminin-binding protein also inhibited fetal
mesangial spreading on the CIKVAVS peptide. Western blot analysis with an
anti-67-kDa laminin-binding protein antibody revealed a 110-kDa protein in
adult mesangial cells that was not present in fetal mesangial
cells.(ABSTRACT TRUNCATED AT 250 WORDS)
