Calvitti M, Baroni T, Calastrini C, Lilli C, Caramelli E, Becchetti E, Carinci P, Vizzotto L, Stabellini G
Experimental Medicine and Biochemistry Science Department, University of Perugia, Italy.
J Histochem Cytochem. 2004 Mar;52(3):325-34. doi: 10.1177/002215540405200303.
During organ differentiation, cell-extracellular matrix (ECM) interactions are required. The components of the ECM, such as glycosaminoglycans, fibronectin, laminin, and collagens, change in relation to cytokine and enzyme activity. Moreover, glycosaminoglycans (GAGs) are components of the ECM that play an important role in both cytokine regulation and cell activities. In this work we studied the accumulation of hyaluronic acid and chondroitin sulfate and heparan sulfate proteoglycans (PGs), beta-N-acetyl-D-glucosaminidase activity, the presence of transforming growth factor beta(2) (TGF beta(2)), and interleukin-1 (IL-1), and the localization of fibronectin, laminin, and collagen I and IV during the early stages of chick embryo lung development. We also determined the levels of hyaluronic acid, chondroitin sulfate, dermatan sulfate, and heparan sulfate GAGs and the activity of beta-N-acetyl-D-glucosaminidase with biochemical methods. Our data show that beta-N-acetyl-D-glucosaminidase activity increases in each cell, especially in the epithelial growth front at the emergence of each bronchial bud, where hyaluronic acid and IL-1 are located in the surrounding mesenchymal areas. Chondroitin sulfate and heparan sulfate PGs, fibronectin, laminin, and collagen I and IV are evident in the area near the basal membrane along the sides where the forming structures are stabilized. Biochemical data show that beta-N-acetyl-D-glucosaminidase activity increases in cells during lung development and is related to GAG decrease and to modifications of the nonsulfated/sulfated GAG ratio. These modifications could change cytokine activity and play an important role in bronchial branching development.
在器官分化过程中，细胞与细胞外基质（ECM）的相互作用是必需的。ECM的成分，如糖胺聚糖、纤连蛋白、层粘连蛋白和胶原蛋白，会随着细胞因子和酶活性的变化而改变。此外，糖胺聚糖（GAGs）是ECM的组成部分，在细胞因子调节和细胞活动中都发挥着重要作用。在这项研究中，我们研究了透明质酸、硫酸软骨素和硫酸乙酰肝素蛋白聚糖（PGs）的积累、β-N-乙酰-D-氨基葡萄糖苷酶活性、转化生长因子β(2)（TGFβ(2)）和白细胞介素-1（IL-1）的存在，以及纤连蛋白、层粘连蛋白、I型和IV型胶原蛋白在鸡胚肺发育早期阶段的定位。我们还通过生化方法测定了透明质酸、硫酸软骨素、硫酸皮肤素和硫酸乙酰肝素GAGs的水平以及β-N-乙酰-D-氨基葡萄糖苷酶的活性。我们的数据表明，每个细胞中的β-N-乙酰-D-氨基葡萄糖苷酶活性都会增加，尤其是在每个支气管芽出现时上皮生长前沿的细胞中，透明质酸和IL-1位于周围的间充质区域。硫酸软骨素和硫酸乙酰肝素PGs、纤连蛋白、层粘连蛋白以及I型和IV型胶原蛋白在沿着形成结构稳定的侧面的基底膜附近区域很明显。生化数据表明，在肺发育过程中细胞内β-N-乙酰-D-氨基葡萄糖苷酶活性增加，并且与GAG减少以及非硫酸化/硫酸化GAG比例的改变有关。这些改变可能会改变细胞因子活性，并在支气管分支发育中发挥重要作用。
