COMPARISON ON COLLAGEN GENE-EXPRESSION IN THE DEVELOPING CHICK-EMBRYO TENDON AND HEART - TISSUE AND DEVELOPMENT TIME-DEPENDENT ACTION OF DEXAMETHASONE
COMPARISON ON COLLAGEN GENE-EXPRESSION IN THE DEVELOPING CHICK-EMBRYO TENDON AND HEART - TISSUE AND DEVELOPMENT TIME-DEPENDENT ACTION OF DEXAMETHASONE
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DOI：
10.1016/0167-4781(91)90082-w
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发表时间：
1991-05-02
期刊：
影响因子：
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通讯作者：
VUORIO, E
中科院分区：
文献类型：
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作者：
OIKARINEN, A;MAKELA, J;VUORIO, E
糖皮质激素调节多种细胞功能，如增殖、能量代谢和蛋白质合成。本研究利用Northern杂交技术和特异的基因探针，研究了鸡胚胎发育不同阶段肌腱和心脏中胶原基因对地塞米松的响应。将胶原基因表达的变化与两个参考mRNAs：肌动蛋白和3-磷酸甘油醛脱氢酶(GAPDH)的变化进行比较。在正常发育过程中，肌腱和心脏中每个核糖体RNA测量到的特定mRNAs水平变化很大。在肌腱中，α-1(I)、α-2(I)和α-1(III)胶原蛋白的相对水平在14-16天时最高，此时基质蛋白的合成也最活跃。在心脏，这些基因的表达水平在第12天达到高峰。此外，肌腱和心脏肌动蛋白基因的表达存在质的差异。大剂量地塞米松可降低肌腱中胶原基因的表达水平，而对心脏有刺激作用。地塞米松也降低了肌腱中GAPDHmRNA的水平。地塞米松处理后肌腱和心脏基因表达的变化与特异性糖皮质激素受体水平无关，后者在鸡胚胎发育过程中变化显著。在肌腱和心脏中，前α-1(I)胶原蛋白的cDNA杂交成两个转录本，分别大小分别为6.2和5.1kb。在鸡胚胎正常发育过程中，心脏中6.2/5.1kb的mRNAs比例显著降低，而肌腱中未见此变化。然而，地塞米松降低了肌腱中6.2/5.1kb转录本的比例。在肌腱和心脏中，6.2/5.1kb转录本与总α-1(I)mRNA之间存在显著的相关性，提示6.2kb转录本可能与I型胶原的合成速度有关。
Glucocorticoids modulate various cellular functions such as proliferation, energy metabolism and the synthesis of proteins. In the present study, the response of collagen genes to dexamethasone in different stages of chick embryo development was studied in tendon and heart using Northern blot analysis and specific cDNA probes. The changes in collagen gene expression were compared to alterations in two reference mRNAs: actin and glyceraldehyde-3-phosphate dehydrogenase (GAPDH). The levels of specific mRNAs measured per ribosomal RNA in tendon and heart varied markedly during normal development. In tendon the relative levels of alpha-1(I), alpha-2(I) and alpha-1(III) collagen mRNAs were highest between days 14-16 when also the synthesis of matrix proteins is most active. In heart the levels of these mRNAs peaked at day 12. In addition, qualitative differences were observed in the expression of actin genes between tendon and heart. Dexamethasone in high dose decreased collagen mRNA levels in tendons, while in heart a stimulatory effect was noted. Dexamethasone also decreased GAPDH mRNA levels in tendons. The alterations in gene expression after dexamethasone treatment in tendon and heart did not correlate with the level of specific glucocorticoid receptors, which varied markedly during the development of chick embryos. The cDNA for pro alpha-1(I) collagen hybridized to two transcripts corresponding to 6.2 and 5.1 kb in tendon and heart. During normal development of chick embryos the ratio of 6.2/5.1 kb mRNAs decreased markedly in heart, but no such change was observed in tendons. Dexamethasone, however, decreased the ratio of 6.2/5.1 kb transcripts in tendons. There was a significant correlation between the ratio 6.2/5.1 kb transcripts and total alpha-1(I) mRNA both in tendon and heart, suggesting that the 6.2 kb transcript may be associated with the rate of synthesis of type I collagen.