Diverse effects of fibronectin and laminin on phenotypic properties of cultured arterial smooth muscle cells.
Diverse effects of fibronectin and laminin on phenotypic properties of cultured arterial smooth muscle cells.
复制标题
纤连蛋白和层粘连蛋白对培养的动脉平滑肌细胞表型特性的各种影响。
DOI：
10.1083/jcb.107.1.307
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发表时间：
1988-07
影响因子：
7.8
通讯作者：
Thyberg, J
中科院分区：
文献类型：
--
作者：
Hedin, U;Bottger, B A;Forsberg, E;Johansson, S;Thyberg, J
在原代培养的最初几天，血浆纤维连接蛋白促进大鼠动脉平滑肌细胞从收缩表型转变为合成表型。这个过程包括细胞的黏附和铺展，肌丝的丢失，以及广泛的粗面内质网和突出的高尔基复合体的形成。伴随着结构重组的是总RNA和蛋白质合成的激活。此外，细胞获得了复制它们的DNA并对血小板衍生生长因子做出反应进行分裂的能力。在这里，已经证明了纤维连接蛋白导致平滑肌细胞分化特性改变的能力存在于105kD的细胞结合片段中，而70kD的胶原结合片段和31kD的肝素结合片段在这方面没有活性。层粘连蛋白是另一种粘附性糖蛋白，也是通常包裹在动脉平滑肌周围的基底膜的一种成分，相反，它被发现保持细胞的收缩表型。然而，随着时间的增加，越来越多的细胞经历了调制，变成了合成表型。这种“追赶”被一种含有纤维连接蛋白细胞附着序列的多肽(Arg-Gly-Asp-Ser)所抵消。因此，层粘连蛋白的延迟调制可能是由于细胞本身产生纤维连接蛋白所致。为了支持这一观点，从平滑肌培养中分离出的纤维连接蛋白被发现在刺激表型改变方面与血浆纤维连接蛋白一样有效。此外，采用化学、免疫化学和免疫细胞化学相结合的方法证明，在原代培养的前4d，细胞分泌纤维连接蛋白和层粘连蛋白的速度加快，值得注意的是，培养在层粘连蛋白上的细胞比培养在纤维连接蛋白上的细胞产生更多的纤维连接蛋白。新合成的纤维连接蛋白被结合到细胞周围和细胞间的纤维网络中，而层粘连蛋白以基底膜的方式形成了一层更弥漫的覆盖细胞的层。综上所述，这些发现表明，纤维连接蛋白和层粘连蛋白在控制动脉平滑肌细胞分化特性方面发挥着不同的作用。他们进一步表明，动脉平滑肌细胞在原代培养早期产生纤维连接蛋白和层粘连蛋白的能力与形态和通过测量总RNA和蛋白质合成速率确定的表型状态没有直接关系。这可能是因为细胞能够感觉到细胞周围基质的大分子组成，并相应地调整它们的分泌活动。
Plasma fibronectin promotes modulation of rat arterial smooth muscle cells from a contractile to a synthetic phenotype during the first few days in primary culture. This process includes cell adhesion and spreading, loss of myofilaments, and formation of a widespread rough endoplasmic reticulum and a prominent Golgi complex. The structural reorganization is accompanied by activation of overall RNA and protein synthesis. Moreover, the cells gain the ability to replicate their DNA and divide in response to platelet-derived growth factor. Here, it is demonstrated that the power of fibronectin to bring about this change in the differentiated properties of the smooth muscle cells resides in a 105-kD cell-binding fragment, whereas a 70-kD collagen-binding fragment and a 31-kD heparin-binding fragment are inactive in this respect. Laminin, another adhesive glycoprotein and a component of the basement membrane that normally surrounds arterial smooth muscle, was contrarily found to maintain the cells in a contractile phenotype. However, with increasing time more and more cells went through the modulation into a synthetic phenotype. This "catch-up" was counteracted by a peptide that contained the cell-attachment sequence of fibronectin (Arg-Gly-Asp-Ser). Hence, it is possible that the delayed modulation on laminin was due to production of fibronectin by the cells themselves. In support of this notion, fibronectin isolated from smooth muscle cultures was found to be as effective as plasma fibronectin in stimulating the phenotypic modulation. Moreover, using a combination of chemical, immunochemical, and immunocytochemical methods, it was demonstrated that the cells secreted fibronectin as well as laminin at an increasing rate during the first 4 d in primary culture and, notably, cells cultured on laminin produced more fibronectin than cells cultured on fibronectin. Newly synthesized fibronectin was incorporated into a network of pericellular and intercellular fibrils, whereas laminin formed a more diffuse layer covering the cells in a basement membrane-like manner. Taken together, the findings suggest diverse roles for fibronectin and laminin in the control of the differentiated properties of arterial smooth muscle cells. They further indicate that the ability of arterial smooth muscle cells to produce fibronectin and laminin early in primary culture is not directly related to the phenotypic state as determined morphologically and by measurement of overall rates of RNA and protein synthesis. This may be due to the cells being able to sense the macromolecular composition of the pericellular matrix and to modify their secretory activity accordingly.(ABSTRACT TRUNCATED AT 400 WORDS)