Co-Authors:
Halevy, O., Department of Animal Science, Faculty of Agriculture, Hebrew University of Jerusalem, Rehovot 76100, Israel, Dept. Biol. Chem. Molec. Pharmacol., Harvard Medical School, Longwood Av. 240, Boston, MA 02115, United States
Monsonego, E., Institute of Animal Science, Agricultural Research Organization, Volcani Center, Bet Dagan 50250, Israel
Marcelle, C., Inst. d'Embryologie, Cell. et Molec., 49 bis, Avenue de la Belle Gabrielle, 94736 Nogent Sur-Marne Cedex, France, Developmental Biology Center, University of California, Irvine, CA 92717, United States
Hodik, V., Department of Animal Science, Faculty of Agriculture, Hebrew University of Jerusalem, Rehovot 76100, Israel
Mett, A., Department of Animal Science, Faculty of Agriculture, Hebrew University of Jerusalem, Rehovot 76100, Israel
Pines, M., Institute of Animal Science, Agricultural Research Organization, Volcani Center, Bet Dagan 50250, Israel
Abstract:
We studied the expression of FREK (fibroblast growth factor receptor-like embryonic kinase), a new receptor recently cloned from quail embryo, during the differentiation of skeletal muscle satellite cells and epiphyseal growth- plate chondrocytes. Although FREK mRNA was expressed in both cell types, satellite cells expressed higher levels of this mRNA than chondrocytes. FREK gene expression was found to be modulated by b-FGF in a biphasic manner: low concentrations increased expression, whereas high concentrations attenuated it. In both cell cultures, the levels of FREK mRNA declined during terminal differentiation. Moreover, retinoic acid (RA), which induces skeletal muscle satellite cells to differentiate, also caused a reduction in FREK gene expression in these cells. Induction of chondrocyte differentiation with ascorbic acid was monitored by a decrease in collagen type II gene expression and an increase in alkaline phosphatase activity. Satellite cell differentiation was marked by morphological changes as well as by increased sarcomeric myogenin content and creatine kinase activity and changes in the expression of the regulatory muscle-specific genes, MyoD and myogenin. DNA synthesis in both cell types was stimulated by b-FGF. However, in satellite cells, the response was bell-shaped, peaking at 1 ng/ml b-FGF, whereas in chondrocytes, higher levels of b-FGF were needed. b-FGF-dependent DNA synthesis in satellite cells was decreased by RA at concentrations over 10- 7 M. The observed correlation between the level of FREK gene expression and various stages of differentiation, its modulation by b-FGF and RA, as well as the correlation between FREK gene expression and the physiological response to b-FGF, suggest that this specific FGF receptor plays an important role in muscle and cartilage cell differentiation.
תפריט נגישות
ניגודיות עדינה
מונוכרום
הדגשת קישורים
חסימת אנימציה
פונט קריא
סגור
איפוס הגדרות נגישות
להורדת מודול נגישות חינם
