Melloni B, Lesur O, Cantin A, Bégin R
Unité de recherche pulmonaire, Université de Sherbrooke, Québec, Canada.
J Leukoc Biol. 1993 Mar;53(3):327-35. doi: 10.1002/jlb.53.3.327.
This study addresses the hypothesis that silica-activated alveolar macrophages could release soluble factors stimulating type II cell proliferation. Macrophages from control sheep were exposed or not in vitro to silica, aluminum-treated silica (Si-Al), or titanium dioxide (TiO2). In addition, macrophages from a model of chromic silica-exposed sheep were studied. Supernatants from unstimulated macrophages were found to double basal type II cell DNA synthesis. Alveolar macrophage-conditioned media (AMCM) collected from cells exposed in vitro to silica induced an additional growth-promoting activity for type II cells. Supernatants from Si-Al- or TiO2 dust-exposed alveolar macrophages had the same effects as unstimulated AMCM. In addition, AMCM from in vivo silicotic sheep cells also contained elevated levels of type II cell mitogenic activity. These results suggest that in vitro as in vivo, silica-activated macrophages produce a type II cell growth factor(s) for type II epithelial cells.
本研究探讨了二氧化硅激活的肺泡巨噬细胞是否能释放刺激II型细胞增殖的可溶性因子这一假说。将对照绵羊的巨噬细胞在体外暴露于二氧化硅、铝处理的二氧化硅（Si-Al）或二氧化钛（TiO2），或不进行暴露处理。此外，还研究了来自慢性二氧化硅暴露绵羊模型的巨噬细胞。未受刺激的巨噬细胞的上清液可使II型细胞的基础DNA合成增加一倍。从体外暴露于二氧化硅的细胞收集的肺泡巨噬细胞条件培养基（AMCM）对II型细胞具有额外的促生长活性。暴露于Si-Al或TiO2粉尘的肺泡巨噬细胞的上清液与未受刺激的AMCM具有相同的作用。此外，来自体内矽肺绵羊细胞的AMCM中II型细胞促有丝分裂活性水平也升高。这些结果表明，在体外和体内，二氧化硅激活的巨噬细胞都会产生针对II型上皮细胞的II型细胞生长因子。
