Zhao J, Warburton D
Department of Surgery, Childrens Hospital Los Angeles Research Institute, University of Southern California School of Dentistry, California 90033, USA.
Am J Physiol. 1997 Jul;273(1 Pt 1):L282-7. doi: 10.1152/ajplung.1997.273.1.L282.
Matrix Gla protein (MGP) is a vitamin K-dependent extracellular matrix protein with a wide tissue distribution. The current study was designed to investigate the possible regulation of MGP by exogenous transforming growth factor-beta (TGF-beta) during lung development. Using reverse transcription coupled competitive polymerase chain reaction methodology, we determined that exogenous TGF-beta 1 increases MGP mRNA levels in embryonic mouse lung culture in a concentration-dependent manner. MGP mRNA levels were elevated by 5.0-fold at 50 ng/ml TGF-beta 1 in E11 embryonic mouse lungs explanted for 4 days in serumless culture. MGP mRNA stimulation by TGF-beta 1 was a time-dependent event: MGP message increment was initially detected after 1 day in culture, and MGP mRNA levels continued to increase up to 4 days in the presence of TGF-beta 1. In addition, embryonic lungs in serumless medium without exogenously added TGF-beta 1 showed an increase, although to a lesser extent, in pulmonary MGP mRNA level during culture, indicating that MGP expression is also developmentally regulated. The present results indicate that MGP gene expression can be stimulated by exogenous TGF-beta 1 during early embryonic mouse lung branching morphogenesis in culture.
基质γ-羧基谷氨酸蛋白（MGP）是一种维生素K依赖的细胞外基质蛋白，广泛分布于多种组织。本研究旨在探讨在肺发育过程中外源转化生长因子-β（TGF-β）对MGP的潜在调控作用。采用逆转录偶联竞争性聚合酶链反应方法，我们确定外源性TGF-β1能以浓度依赖的方式增加胚胎小鼠肺组织培养物中MGP的mRNA水平。在无血清培养基中培养4天的E11胚胎小鼠肺组织，当TGF-β1浓度为50 ng/ml时，MGP的mRNA水平升高了5.0倍。TGF-β1对MGP mRNA的刺激是一个时间依赖性事件：在培养1天后最初检测到MGP信息增加，在TGF-β1存在的情况下，MGP mRNA水平持续增加至4天。此外，在无外源性添加TGF-β1的无血清培养基中培养的胚胎肺组织，在培养过程中肺组织MGP mRNA水平也有增加，尽管增加幅度较小，这表明MGP的表达也受发育调控。目前的结果表明，在培养的早期胚胎小鼠肺分支形态发生过程中，外源性TGF-β1可刺激MGP基因表达。
