The role of Nkx3.2 in chondrogenesis

Transcription factor, Nkx3.2, is a member of the NK family of developmental genes and is expressed during embryogenesis in a variety of mammalian model organisms, including chicken and mouse. It was first identified in Drosophila as the Bagpipe （bap） gene, where it has been demonstrated to be essential during formation of the midgut musculature. However, mammalian homolog Nkx3.2 has been shown to play a significant role in axial and limb skeletogenesis; in particular, the human skeletal disease, spondylo-megaepiphyseal-metaphyseal dysplasia （SMMD）, is associated with mutations of the Nkx3.2 gene. In this review, we highlight the role of Nkx3.2 during musculoskeletal development, with an emphasis on the factor＇s role in determining chondrogenic cell fate and its subsequent role in endochondral ossification and chondrocyte survival.

髋关节骨性关节炎软骨组织Col2a1和Nkx3．2的表达水平及临床意义

目的探讨髋关节骨性关节炎软骨组织中Ⅱ型胶原α1链（Col2a1）和人同源盒基因Nkx3．2的表达水平及临床意义。方法收集36例髋关节骨性关节炎患者的软骨组织样本，采用RT—PCR法检测Col2a1和Nkx3．2的mRNA水平，Westernblot法检测样本中两指标的蛋白水平；分析不同病理参数的Col2a1和Nkx3．2的mRNA和蛋白水平。并选取同期的39例股骨颈骨折患者作对照。结果髋关节骨性关节炎患者的Col2a1和Nkx3．2的mRNA和蛋白水平均高于股骨颈骨折患者（P〈0．05）；髋关节骨性关节炎患者两指标的mRNA和蛋白水平在年龄、类型、病程、ISOA、K—L放射线分级及严重程度上有统计学差异（P〈0．05或0．01），在性别和侧别上无统计学差异（P〉0．05）。结论髋关节骨性关节炎软骨组织中Col2a1和Nkx3．2的表达水平上调，且在多数病理参数分布上有差异，提示两者在骨性关节炎软骨组织退变中起作用，可用于该疾病的诊断和治疗方案制订。