Composition in situ and in vitro of vascular smooth muscle laminin in the rat.
Composition in situ and in vitro of vascular smooth muscle laminin in the rat.
复制标题
大鼠血管平滑肌层粘连蛋白的原位和体外组成。
DOI：
10.1007/bf00307973
复制
发表时间：
1995
影响因子：
3.6
通讯作者：
McGuffee,LJ
中科院分区：
文献类型：
--
作者：
Walker-Caprioglio,HM;Hunter,DD;McGuire,PG;Little,SA;McGuffee,LJ
血管平滑肌细胞被含有一系列大分子的基底层包围：其中包括层粘连蛋白，这是一个由不同基因编码的亚基组成的寡聚糖蛋白家族。在本研究中，我们使用针对其中几个亚基（包括 S-层粘连蛋白、层粘连蛋白 B2 和层粘连蛋白 B1）的单克隆抗体来研究大鼠尾动脉、肠系膜上动脉和主动脉中的这些蛋白质。在原位，B2 和 S 链的免疫染色存在于基底层、平滑肌细胞之间和整个中膜中。相反，B1 链免疫染色集中在内部介质中的细胞周围。为了研究平滑肌细胞是否可以产生S-层粘连蛋白、层粘连蛋白B2和层粘连蛋白B1，在培养物中培养来自肠系膜上动脉的平滑肌细胞并测定层粘连蛋白亚基表达。在早期培养（4 天）中，免疫染色显示层粘连蛋白 B2 丰富，B1 合成和掺入基质较少。 S-层粘连蛋白的染色强度甚至低于 B1，并且局限于细胞密集的区域。在纤连蛋白、IV 型胶原或明胶上生长的细胞的早期培养过程中，观察到相同的 S-层粘连蛋白免疫染色模式。免疫印迹检测到早期培养细胞的条件培养基中的 S-层粘连蛋白。在培养后期（12 天），与 4 天时的掺入相比，S-层粘连蛋白掺入基质显着增加。此时，细胞更加密集和多层，并具有广泛的基质积累。体外细胞的周期性拉伸不会增加 S-层粘连蛋白的免疫染色。这些数据共同表明，S-层粘连蛋白是原位动脉介质的成分，并且体外S-层粘连蛋白是由平滑肌细胞合成的。在后来的培养中，S-层粘连蛋白掺入基质的增加与更广泛基质的存在相关，这表明基质组织可能对 S-层粘连蛋白掺入至关重要。
Vascular smooth muscle cells are surrounded by a basal lamina containing an array of macromolecules: included among these are the laminins, a family of oligomeric glycoproteins composed of subunits encoded by different genes. In this study, we have used monoclonal antibodies to several of these subunits, including S-laminin, laminin B2, and laminin B1, to study these proteins in tail artery, superior mesenteric artery, and aorta of rats. In situ, immunostaining for the B2 and S chains was present in the basal lamina, between the smooth muscle cells, throughout the tunica media. In contrast, B1 chain immunostaining was concentrated around cells in the inner media. To investigate whether smooth muscle cells can produce S-laminin, laminin B2, and laminin B1, smooth muscle cells from the superior mesenteric artery were grown in culture and laminin subunit expression determined. In early culture (4 days), immunostaining showed abundant laminin B2 and less B1 synthesis and incorporation into the matrix. Staining for S-laminin was even less intense than for B1 and was localized to areas where cells were densely packed. The same pattern of S-laminin immunostaining was seen during early culture in cells grown on fibronectin, type IV collagen, or gelatin. Immunoblotting detected S-laminin in the conditioned medium from early cultured cells. In later culture (12 days), S-laminin incorporation into the matrix increased markedly compared to incorporation at 4 days. At this time, cells are much more densely packed and multilayered with extensive matrix accumulation. Cyclical stretching of cells in vitro did not increase immunostaining for S-laminin. Together these data show that S-laminin is a component of the arterial media in situ and that in vitro S-laminin is synthesized by smooth muscle cells. Increased incorporation of S-laminin into the matrix in later culture correlates with the presence of a more extensive matrix, suggesting that matrix organization may be critical to S-laminin incorporation.