Basic fibroblast growth factor as a selective inducer of matrix Gla protein gene expression in proliferative chondrocytes.
Basic fibroblast growth factor as a selective inducer of matrix Gla protein gene expression in proliferative chondrocytes.
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碱性成纤维细胞生长因子作为增殖软骨细胞中基质 Gla 蛋白基因表达的选择性诱导剂。
作者：
Chantal Stheneur;M. Dumontier;Claudie Guedes;M. Fulchignoni;K. Tahiri;G. Karsenty;M. Corvol
基质Gla蛋白（MGP）是在软骨中表达的维生素K依赖性γ羧化酶蛋白家族的成员。胰岛素样生长因子I（IGF 1）刺激软骨细胞分化，而碱性成纤维细胞生长因子（FGF 2）以相反的方式起作用。我们探讨了软骨细胞分化过程中MGP基因的差异表达和IGF 1和FGF 2的调控。我们使用原代培养系统的兔骺软骨细胞显示，MGP mRNA主要表达在血清诱导的增殖。在有丝分裂后软骨细胞中观察到低得多的MGP mRNA含量，其新表达α 1X前胶原mRNA，这是晚期分化细胞的标志物。对一系列生长因子的研究表明，IGF1降低软骨细胞MGP转录，而FGF2具有相反的作用。FGF2在mRNA和蛋白水平上以剂量和时间依赖性的方式刺激软骨细胞MGP的产生。FGF 2以剂量和时间依赖性方式起作用，在20 h时达到最大值10 ng/ml。蛋白质合成抑制剂放线菌酮没有改变FGF2的作用，与直接作用一致。放线菌素D消除FGF 2诱导的刺激，强烈表明FGF 2调制MGP基因转录。我们用含有小鼠MGP启动子的构建体瞬时转染软骨细胞，所述启动子相对于与荧光素酶基因连接的基因的转录起始位点为-5000至-168碱基对（MGP-Luc）。在转染的细胞中，FGF 2刺激荧光素酶活性高达7倍，而IGF 1没有影响。因此，FGF2通过基因的5 '侧翼区诱导MGP基因的转录。使用一系列缺失的MGP-Luc构建体，我们鉴定了足以通过FGF 2转录激活的748个碱基对的序列。这些结果使我们推测FGF2的抑制性软骨形成作用涉及诱导MGP基因转录和蛋白质的机制。
Matrix Gla protein (MGP) is a member of the vitamin K-dependent gamma carboxylase protein family expressed in cartilage. Insulin-like growth factor I (IGF1) stimulates chondrocyte differentiation, whereas basic fibroblast growth factor (FGF2) acts in an opposite manner. We explored the differential expression and regulation by IGF1 and FGF2 of the MGP gene during chondrocyte differentiation. We used a primary culture system of rabbit epiphyseal chondrocytes to show that MGP mRNA is mainly expressed during serum-induced proliferation. Much lower MGP mRNA content is observed in post-mitotic chondrocytes, which newly express alpha 1X procollagen mRNA, a marker of late-differentiated cells. From studies of a series of growth factors, it was shown that IGF1 decreased chondrocyte MGP transcripts, whereas FGF2 had the opposite effect. FGF2 stimulated chondrocyte MGP production in a dose- and time-dependent manner at the mRNA and protein levels. FGF2 acted in a dose- and time-dependent manner, reaching a maximum at 10 ng/ml at 20 h. The protein synthesis inhibitor cycloheximide did not modify FGF2 action, in agreement with a direct effect. Actinomycin D abolished FGF2-induced stimulation, strongly suggesting that FGF2 modulated MGP gene transcription. We transiently transfected chondrocytes with a construct containing the mouse MGP promoter from -5000 to -168 base pairs, relative to the transcription start site of the gene linked to the luciferase gene (MGP-Luc). In transfected cells, FGF2 stimulated luciferase activity up to sevenfold while IGF1 had no effect. Hence, FGF2 induces transcription of the MGP gene via the 5'-flanking region of the gene. Using a series of deleted MGP-Luc constructs, we identified a sequence of 748 base pairs which was sufficient for transcriptional activation by FGF2. These results led us to postulate that the inhibitory chondrogenic action of FGF2 involves a mechanism whereby MGP gene transcription and protein are induced.
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影响因子：
14.9
作者：
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DOI：
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发表时间：
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期刊：
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影响因子：
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作者：
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通讯作者：
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DOI：
10.1073/pnas.97.3.1113
发表时间：
2000-02-01
影响因子：
11.1
作者：
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DOI：
--
发表时间：
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期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Otawara,Y;Price,PA
通讯作者：
Price,PA
DOI：
10.1073/pnas.79.24.7734
发表时间：
1982-01-01
期刊：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
影响因子：
--
作者：
PRICE, PA;WILLIAMSON, MK;JEE, WSS
通讯作者：
JEE, WSS