Kocher O, Skalli O, Cerutti D, Gabbiani F, Gabbiani G
Circ Res. 1985 Jun;56(6):829-38. doi: 10.1161/01.res.56.6.829.
Actin, vimentin, desmin, and tropomyosin distribution in rat aortic endothelial and smooth muscle cells has been studied during development using fetal (18 to 20 days of gestation), and 5- and 14-day-, and 5-, and 12-week-old rats. Endothelial cells of newborn animals actively replicate and contain many actin stress fibers, whereas, in adult animals, replication is minimal and actin stress fibers are rare. The actin, vimentin, desmin, and tropomyosin content of smooth muscle cells increases gradually from fetal to adult animals. The number of desmin-containing cells also increases from 13% in fetal rats to 51% in adult rats. The beta-actin isoform is predominant in fetal and newborn animals, but gradually the alpha-isoform becomes quantitatively the most important, as seen by bidimensional polyacrylamide gels. Several analogies exist between the features of developing smooth muscle and what is known for developing striated muscle cells. The evolution of cytoskeletal features from fetal to adult animals is remarkably the opposite of what takes place in: (1) rat aortic smooth muscle cells proliferating after an endothelial injury, (2) human arterial smooth muscle cells present in atheromas, and (3) actively growing rat aortic smooth muscle cells in vitro. Thus, the assumption that pathological or cultured smooth muscle cells are "dedifferentiated" is supported by our biochemical observations.
利用胎鼠（妊娠18至20天）以及出生5天、14天、5周和12周龄的大鼠，研究了大鼠主动脉内皮细胞和平滑肌细胞中肌动蛋白、波形蛋白、结蛋白和原肌球蛋白在发育过程中的分布情况。新生动物的内皮细胞积极进行复制，含有许多肌动蛋白应力纤维，而成年动物中，细胞复制极少，肌动蛋白应力纤维也很罕见。从胎儿到成年动物，平滑肌细胞中的肌动蛋白、波形蛋白、结蛋白和原肌球蛋白含量逐渐增加。含结蛋白的细胞数量也从胎鼠的13%增加到成年大鼠的51%。通过双向聚丙烯酰胺凝胶电泳可见，β-肌动蛋白异构体在胎儿和新生动物中占主导，但逐渐地，α-异构体在数量上变得最为重要。发育中的平滑肌的特征与已知的发育中的横纹肌细胞的特征之间存在若干相似之处。从胎儿到成年动物，细胞骨架特征的演变与以下情况明显相反：（1）内皮损伤后增殖的大鼠主动脉平滑肌细胞，（2）动脉粥样硬化斑块中存在的人动脉平滑肌细胞，以及（3）体外积极生长的大鼠主动脉平滑肌细胞。因此，我们的生化观察结果支持了病理性或培养的平滑肌细胞是“去分化的”这一假设。
