Notch and HES5 are regulated during human cartilage differentiation
Notch and HES5 are regulated during human cartilage differentiation
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DOI：
10.1007/s00441-006-0307-0
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发表时间：
2007-03-01
影响因子：
3.6
通讯作者：
Lindahl, Anders
中科院分区：
文献类型：
--
作者：
Karlsson, Camilla;Jonsson, Marianne;Lindahl, Anders
软骨分化的分子机制尚不清楚。在软骨以外的多种组织中，碱性螺旋-环-螺旋(BHLH)转录因子家族的成员已被证明在分化中发挥关键作用。我们已经鉴定了人类bHLH基因HES5，并研究了它在软骨形成中的作用。用一种伽马分泌酶抑制剂阻断Notch信号通路表明，人类HES5基因是关节软骨细胞Notch信号的下游标志。在体外软骨分化过程中，Notch信号通路的标志物显著减少。BrdU法检测细胞增殖情况表明，阻断Notch信号转导通路与细胞增殖显著降低有关。Northern印迹和逆转录/聚合酶链式反应表明，HES5转录为5.4kb的mRNA，在不同的胎儿和成人组织中普遍表达。对HES5(-/-)和野生型小鼠的关节软骨进行了各种组织学染色分析。野生型和HES5(-/-)小鼠之间没有发现差异。因此，我们的数据表明人类HES5基因与Notch受体家族偶联，在软骨分化过程中Notch标志物(包括HES5)的表达减少，并且Notch信号的阻断与细胞增殖显著降低有关。
The molecular mechanisms of cartilage differentiation are poorly understood. In a variety of tissues other than cartilage, members of the basic helix-loop-helix (bHLH) family of transcription factors have been demonstrated to play critical roles in differentiation. We have characterized the human bHLH gene HES5 and investigated its role during chondrogenesis. Blockage of the Notch signaling pathway with a gamma-secretase inhibitor has demonstrated that the human HES5 gene is a downstream marker of Notch signaling in articular chondrocytes. Markers for the Notch signaling pathway significantly decrease during cartilage differentiation in vitro. Cell proliferation assayed by using BrdU has revealed that blockage of Notch signaling is associated with significantly decreased proliferation. Northern blot and reverse transcription/polymerase chain reaction of a panel of various tissues have shown that HES5 is transcribed as a 5.4-kb mRNA that is ubiquitously expressed in diverse fetal and adult tissues. Articular cartilage from HES5(-/-) and wild-type mice has been analyzed by using various histological stains. No differences have been detected between the wild-type and HES5(-/-) mice. Our data thus indicate that the human HES5 gene is coupled to the Notch receptor family, that expression of Notch markers (including HES5) decreases during cartilage differentiation, and that the blockage of Notch signaling is associated with significantly decreased cell proliferation.