Adult human chondrocytes cultured in alginate form a matrix similar
to native human articular cartilage.
H[umlaut]auselmann, Hans. J., Koichi Masuda, Ernst B. Hunziker, Michel
Neidhart, Su S. Mok, Beat A. Michel, and Eugene J. M. A. Thonar.
Departments of Biochemistry and Internal Medicine (Section of
Rheumatology), Rush Medical College at Rush-Presbyterian-St. Luke's
Medical Center, Chicago IL 60612, USA, Department of Rheumatology,
University Hospital, CH-8091 Z[umlaut]urich, Switzerland, and
ŻglhiddenŻM.E. M[umlaut]uller Institute for Biomechanics, University
of Bern, CH-3010 Bern, Switzerland
APStracts 3:0067C, 1996.
The matrix formed by adult human chondrocytes in alginate beads is
composed of two compartments: a thin rim of cell-associated matrix
which corresponds to the pericellular and territorial matrix of
articular cartilage and a more abundant further-removed matrix, the
equivalent of the interterritorial matrix in the tissue. On day 30 of
culture, the relative and absolute volumes occupied by the cells and
each of the two matrix compartments in the beads were nearly
identical to those in native articular cartilage. Further, the
concentration of aggrecan in the cell-associated matrix was similar
to that in adult human articular cartilage and was approximately 40
-fold higher than in the further removed matrix compartment.
Fluorescence-activated cell sorting revealed that the cell-associated
matrix was built upon the cell membrane in part via interactions
between hyaluronan and CD44-like receptors. Approximately 25% of the
aggrecan molecules synthesized by the chondrocytes during a 4 h pulse
in the presence of 35S-sulfate on day 9 of culture were retained in
the cell-associated matrix where they turned over with a t1/2= 29
days. Most 35S-aggrecan molecules reached the further removed matrix
compartment where they turned over much more slowly (t1/2 >100
days). These results add support to the contention that aggrecan
molecules residing in the pericellular and territorial areas of the
adult human articular cartilage matrix are more susceptible to
degradation by proteolytic enzymes synthesized by the chondrocytes
than those which inhabit the interterritorial areas further removed
from the cells.
Received 16 October 1995; accepted in final form 21 February
1996.
APS Manuscript Number C629-5.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 13 March 96