25-羟基胆固醇促进培养的家兔主动脉中膜细胞体外钙化

25-Hydroxycholesterol Accelerates in Vitro Calcification of Rabbit Aortic Medial Cells

为研究主动脉中膜细胞体外钙化情况以及 2 5 -羟基胆固醇对此过程的促进作用 ,采用贴块法分离培养主动脉中膜细胞 ,并进行vonKossa染色以显示钙化 ,生物化学检测细胞不溶性钙 ,放射免疫法测定培养上清液中骨钙素含量。发现原代细胞有两种生长表现 :一种细胞平行生长 ,不形成结节 ,vonKossa染色阴性 ;另一种易形成结节 ,vonKossa染色阳性。对照组传代细胞培养 2 8天无结节形成 ,vonKossa染色阴性。而实验组 ,即 2 5 -羟基胆固醇处理组有细胞结节形成 ,vonKossa染色阳性 ,培养上清液中骨钙素增多。由此可见体外培养的主动脉中膜细胞有两种亚型 ,一种为平滑肌细胞的表型 ;另一种为微血管周细胞型细胞 ,能使其细胞外基质钙化。 2 5 -羟基胆固醇可以促进这一体外钙化过程。周细胞型细胞钙化过程中骨钙素合成增多 ,推测骨钙素可能参与了主动脉的钙化。

Aim To investigate in vitro calcification of aortic medial cells and the acceleration by 25-hydroxycholesterol. Methods Aortic medial cells were obtained by explantation. Von Kossa staining was performed to show calcification. Insoluble calcium of cellular layer was determined by biochemical method. And osteocalcin in the media was analyzed with radioimmunoassay. Results Primary cells appeared two different types: cells with the features of parallel growth and negative von Kossa staining, and cells forming nodules with positive von Kossa staining. Passaged cells formed no nodules after 28 days. Cells treated with 25-hydroxycholesterol appeared many cell nodules with positive von Kossa staining. Both insoluble calcium and medium osteocalcin increased significantly. Conclusions There are two subgroups of the cultured aortic medial cells: one with the characters of smooth muscle cells; the other like micro vascular pericytes, which can calcify the extracellular matrix. 25-hydroxycholesterol can promote in vitro calcification. Osteocalcin secretion increases during pericyte-like cell calcification, suggesting that osteocalcin may take part in aortic calcification.