Arciniegas Enrique, Neves Carmen Yudith, Candelle Daniel, Parada David
Laboratorio de Microscopía Electrónica, Servicio Autónomo Instituto de Biomedicina, Facultad de Medicina, Universidad Central de Venezuela, Caracas, Venezuela.
Anat Rec A Discov Mol Cell Evol Biol. 2004 Jul;279(1):592-600. doi: 10.1002/ar.a.20042.
Members of the family of large chondroitin sulfate proteoglycans (CSPGs), such as versican and aggrecan, are involved in early heart development, and in the development and progression of atherosclerosis and restenosis. Given the important roles played by versican and aggrecan in such processes, we sought to determine whether these molecules are present in the aortic wall during the advanced stages of chicken embryo development and the endothelial-mesenchymal transformation (EMT). Immunolabeling of serial cryosections revealed versican immunoreactivity around the cells within the intimal thickening, and the cells organized in lamellar and interlamellar cell layers. In contrast, a weak aggrecan immunoreactivity was limited to the cells arranged into lamellar and interlamellar cell layers. Immunolabeling also demonstrated that V2 is the main versican isoform present at the intimal thickening. According to immunoblotting analysis, the aggrecan content was very low in all stages examined, and two versican isoforms (V0 and V2) were present at day 14 of development. We also investigated whether versican isoforms were present during EMT in vitro. Versican immunoreactivity was detected in patches of endothelial cells; in the detaching and migrating cells, and the extracellular matrix (ECM) deposited by them; and in cells that had acquired mesenchymal characteristics. These data indicate that versican and aggrecan have different spatial and temporal patterns of expression, and they have different functions during remodeling of the aortic wall. Also, the different immunoreactivity and immunolocalization patterns observed for versican both in vivo and in vitro, in addition to being associated with the presence of different versican isoforms, may be related to the predominance of the V2 isoform during intimal thickening formation and EMT.
硫酸软骨素蛋白聚糖（CSPG）大家族的成员，如多功能蛋白聚糖和聚集蛋白聚糖，参与心脏早期发育以及动脉粥样硬化和再狭窄的发生发展过程。鉴于多功能蛋白聚糖和聚集蛋白聚糖在此类过程中发挥的重要作用，我们试图确定在鸡胚发育晚期和内皮-间充质转化（EMT）过程中，这些分子是否存在于主动脉壁中。对连续冰冻切片进行免疫标记显示，多功能蛋白聚糖免疫反应性出现在内膜增厚处的细胞周围，以及排列成层状和层间细胞层的细胞中。相比之下，聚集蛋白聚糖的弱免疫反应性仅限于排列成层状和层间细胞层的细胞。免疫标记还表明，V2是内膜增厚处存在的主要多功能蛋白聚糖异构体。根据免疫印迹分析，在所检测的所有阶段，聚集蛋白聚糖含量都非常低，在发育第14天时存在两种多功能蛋白聚糖异构体（V0和V2）。我们还研究了多功能蛋白聚糖异构体在体外EMT过程中是否存在。在贴壁的内皮细胞斑块中、在脱离和迁移的细胞及其分泌的细胞外基质（ECM）中以及在已获得间充质特征的细胞中检测到了多功能蛋白聚糖免疫反应性。这些数据表明，多功能蛋白聚糖和聚集蛋白聚糖具有不同的时空表达模式，并且它们在主动脉壁重塑过程中具有不同的功能。此外，在体内和体外观察到的多功能蛋白聚糖不同的免疫反应性和免疫定位模式，除了与不同多功能蛋白聚糖异构体的存在有关外，可能还与内膜增厚形成和EMT过程中V2异构体的优势有关。
