TY - JOUR
T1 - Modification of plasma membrane of differentiating preosseous chondrocytes
T2 - Evidence for a degradative process in the mechanism of matrix vesicle formation
AU - Pollesello, Piero
AU - D'Andrea, Paola
AU - Martina, Marco
AU - de Bernard, Benedetto
AU - Vittur, Franco
N1 - Funding Information:
We thank Professor R. Marzari for the kind suggestions and Mr. G. C. Lunazzi for the supply of antiserum against alkaline phosphatase. We also acknowledge the “Fond0 per lo studio delle malattie de1 fegato,” which allowed us to use the spectrofluorometer, and the Ua-netto & Borghese delicatessen factory for the generous supply of pig scapulas. This work was supported by CNR and MPI, Italy.
PY - 1990/6
Y1 - 1990/6
N2 - Chondrocytes of the growth plate are differentiating cells. Their evolution leads to matrix vesicle formation and to cartilage mineralization. This is an in vitro study of the plasma membrane of Chondrocytes at two differentiation stages. Differences in protein and glycoprotein components, increased membrane fluidity, and responsiveness to PTH indicate that hypertrophic ("ossifying") Chondrocytes possess a plasma membrane widely different from that of resting Chondrocytes. Their plasma membrane is particularly enriched in alkaline phosphatase (Mr 70K). Purified matrix vesicles contain the 70K form of alkaline phosphatase, but a 50K species is also detectable, a signal of degradative process. In fact, proteins and glycoproteins of matrix vesicles are less numerous than those of cell plasma membranes. It is suggested that, in vivo, matrix vesicle formation may be mediated by Ca2+-activated neutral proteases.
AB - Chondrocytes of the growth plate are differentiating cells. Their evolution leads to matrix vesicle formation and to cartilage mineralization. This is an in vitro study of the plasma membrane of Chondrocytes at two differentiation stages. Differences in protein and glycoprotein components, increased membrane fluidity, and responsiveness to PTH indicate that hypertrophic ("ossifying") Chondrocytes possess a plasma membrane widely different from that of resting Chondrocytes. Their plasma membrane is particularly enriched in alkaline phosphatase (Mr 70K). Purified matrix vesicles contain the 70K form of alkaline phosphatase, but a 50K species is also detectable, a signal of degradative process. In fact, proteins and glycoproteins of matrix vesicles are less numerous than those of cell plasma membranes. It is suggested that, in vivo, matrix vesicle formation may be mediated by Ca2+-activated neutral proteases.
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U2 - 10.1016/0014-4827(90)90162-4
DO - 10.1016/0014-4827(90)90162-4
M3 - Article
C2 - 2159402
AN - SCOPUS:0025331326
SN - 0014-4827
VL - 188
SP - 214
EP - 218
JO - Experimental Cell Research
JF - Experimental Cell Research
IS - 2
ER -