Foreman D M, Sharpe P M, Ferguson M W
Department of Cell and Structural Biology, University of Manchester, U.K.
Arch Oral Biol. 1991;36(6):457-71. doi: 10.1016/0003-9969(91)90137-j.
A biochemical study analysing the wet weight, dry weight, water, protein and DNA content, collagen and GAG composition of all stages of the developing secondary palate in vivo and in vitro was undertaken to investigate differences between a species in which the palatal shelves elevate (mouse) and one in which they do not (chick). The effects of EGF, bFGF, PDGF and TFG-beta 1 on collagen and GAG synthesis by cultured mouse and chick palatal shelves of different embryonic stages were also studied. The total GAG content of developing mouse palatal shelves decreased with developmental time; heparan sulphate proteoglycan formed the major species in early palates but hyaluronan was the major species in mid-late palates. There was a peak of hyaluronan synthesis in embryonic palatal shelves in vitro at day 13 (T.21), i.e. immediately before shelf elevation. By contrast the total GAG content of chick palates increased with development; chondroitin-6-sulphate formed the major GAG species and there was no peak in hyaluronan synthesis. The water content of developing murine palates rose rapidly at day 14 (T.22), i.e. the time of shelf elevation. No such peak was seen in the chick, where the water content rose exponentially with developmental time. Mouse palates synthesized chondroitin-4-sulphate and novel proteins around the time of shelf elevation; chick palates synthesized chondroitin-6-sulphate and no novel proteins at any developmental stage. Collagen synthesis also peaked in vitro in T.21 murine palates. EGF markedly stimulated murine palatal collagens and GAG synthesis between stages T.20-T.22, but had no effect thereafter. Basic FGF had similar but smaller stage-related effects. PDGF had no effect on mouse palatal collagen and GAG synthesis whilst TGF-beta 1 inhibited GAG synthesis at T.21. The ratios of collagens I, III and V produced by mouse palates were unaltered by the growth factors. All the growth factors had no effect on chick palatal collagen synthesis at any stage and minimal effect on GAG synthesis; TGF-beta 1 stimulated it in early but inhibited it in mid- to late-stage chick palates. These data indicate that extracellular matrix molecule metabolism within the palate is markedly different in the two species studied and suggest that the differing profiles of such molecules may be regulated at certain developmental stages by specific growth factors.
进行了一项生化研究，分析体内和体外发育中的次生腭各阶段的湿重、干重、水分、蛋白质和DNA含量、胶原蛋白和糖胺聚糖组成，以研究腭突能抬高的物种（小鼠）和不能抬高的物种（鸡）之间的差异。还研究了表皮生长因子（EGF）、碱性成纤维细胞生长因子（bFGF）、血小板衍生生长因子（PDGF）和转化生长因子-β1（TGF-β1）对不同胚胎阶段培养的小鼠和鸡腭突胶原蛋白和糖胺聚糖合成的影响。发育中小鼠腭突的总糖胺聚糖含量随发育时间而降低；硫酸乙酰肝素蛋白聚糖在早期腭突中占主要成分，但透明质酸在中晚期腭突中占主要成分。在体外培养的胚胎腭突中，透明质酸合成在第13天（T.21）达到峰值，即正好在腭突抬高之前。相比之下，鸡腭突的总糖胺聚糖含量随发育而增加；硫酸软骨素-6-硫酸盐是主要的糖胺聚糖种类，透明质酸合成没有峰值。发育中小鼠腭突的水分含量在第14天（T.22）迅速上升，即腭突抬高的时间。在鸡中未观察到这样的峰值，其水分含量随发育时间呈指数上升。小鼠腭突在腭突抬高前后合成硫酸软骨素-4-硫酸盐和新蛋白质；鸡腭突在任何发育阶段都合成硫酸软骨素-6-硫酸盐且不合成新蛋白质。胶原蛋白合成在T.21小鼠腭突的体外培养中也达到峰值。表皮生长因子在T.20 - T.22阶段显著刺激小鼠腭突胶原蛋白和糖胺聚糖合成，但此后没有作用。碱性成纤维细胞生长因子有类似但较小的阶段相关作用。血小板衍生生长因子对小鼠腭突胶原蛋白和糖胺聚糖合成没有作用，而转化生长因子-β1在T.21抑制糖胺聚糖合成。小鼠腭突产生的I、III和V型胶原蛋白的比例不受生长因子影响。所有生长因子在任何阶段对鸡腭突胶原蛋白合成均无作用，对糖胺聚糖合成作用极小；转化生长因子-β1在早期刺激鸡腭突糖胺聚糖合成，但在中晚期抑制。这些数据表明，在所研究的两个物种中，腭部细胞外基质分子代谢明显不同，并表明这些分子的不同谱型可能在某些发育阶段受特定生长因子调控。
