TY - JOUR
T1 - Decrease in cytosolic free Ca2+ and enhanced proteoglycan synthesis induced by cartilage derived growth factors in cultured chondrocytes
AU - Eilam, Y.
AU - Beit-Or, A.
AU - Nevo, Z.
PY - 1985/10/30
Y1 - 1985/10/30
N2 - Cartilage-derived growth factors, enhance proteglycan synthesis in cultured chick-embryo chondrocytes, and have almost no effect on cell proliferation. Addition of carilage derived growth factors to cartilage cells loaded with the fluorescent Ca2+ indicator quin 2, caused a rapid, concentration dependent decrease in cytoplasmic free Ca2+. This decrease persisted also in Ca2+-free medium, indicating that it is not mediated by a decrease in the passive permeability of cell membrane to Ca2+. Addition of the Ca2+ ionophore A23187, with or without cartilage derived factors, caused an increase in cytoplasmic free Ca2+ together with inhibition of proteoglycan synthesis and enhanced cell proliferation. The results may indicate that whereas cell proliferation in chondrocytes is signaled by an increase in cytoplasmic Ca2+ ([Ca2+]in), proteoglycan synthesis is signaled by a decrease in [Ca2+]in. The data lead to suggesting a mechanism for antagonistic regulation of cell proliferation and the expression of the differentiated state.
AB - Cartilage-derived growth factors, enhance proteglycan synthesis in cultured chick-embryo chondrocytes, and have almost no effect on cell proliferation. Addition of carilage derived growth factors to cartilage cells loaded with the fluorescent Ca2+ indicator quin 2, caused a rapid, concentration dependent decrease in cytoplasmic free Ca2+. This decrease persisted also in Ca2+-free medium, indicating that it is not mediated by a decrease in the passive permeability of cell membrane to Ca2+. Addition of the Ca2+ ionophore A23187, with or without cartilage derived factors, caused an increase in cytoplasmic free Ca2+ together with inhibition of proteoglycan synthesis and enhanced cell proliferation. The results may indicate that whereas cell proliferation in chondrocytes is signaled by an increase in cytoplasmic Ca2+ ([Ca2+]in), proteoglycan synthesis is signaled by a decrease in [Ca2+]in. The data lead to suggesting a mechanism for antagonistic regulation of cell proliferation and the expression of the differentiated state.
UR - http://www.scopus.com/inward/record.url?scp=0022337332&partnerID=8YFLogxK
U2 - 10.1016/0006-291X(85)91199-4
DO - 10.1016/0006-291X(85)91199-4
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AN - SCOPUS:0022337332
SN - 0006-291X
VL - 132
SP - 770
EP - 779
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 2
ER -