钙对成骨细胞活性、[Ca^(2+)]_i及GJIC的影响

Effect of calcium on cytoactive,[Ca^(2+)]_i and GJIC of osteoblasts in vitro

在体外培养4日龄SD大鼠成骨细胞(OB)的基础上,添加不同浓度钙(0、1、2、4mmol/L),钙作用2d后,观察细胞活性、间隙连接通讯(GJIC),测定钙离子([Ca2+]i)浓度;钙作用2、5、8d测定OB内总蛋白及Ⅰ型胶原(Col-Ⅰ)含量。与对照组比较,钙作用2d后,OB内线粒体增多,内质网扩张,细胞内[Ca2+]i浓度增加,GJIC的荧光扩散距离缩小。总蛋白含量,在2d,钙1、4mmol/L组高于(P<0.05或P<0.01)对照组,在5、8d低于对照组,但仅在8d差异显著(P<0.05或P<0.01)。第2天后,钙抑制Col-Ⅰ分泌(P<0.01),在5、8d均促进(P<0.05或P<0.01)其分泌。结果表明,添加钙作用2d后,促进OB代谢及[Ca2+]i沉积,抑制细胞间通讯,促进总蛋白分泌,抑制Col-Ⅰ分泌,促进了细胞增殖。增殖期过后,则抑制总蛋白分泌,促进Col-Ⅰ分泌,使OB较早的进入基质成熟期,利于骨骼的重建。

Osteoblasts（OBs）were cultured in media with calcium（Ca）（0,1,2and 4mmol/L）.After 2day treated by Ca,cytoactive,gap junction intercellular communication（GJIC）were observed,and intracellular Ca2＋（[Ca2＋]i）were evaluated.At 2,5and 8day incubation with Ca,total protein,collagenⅠ（Col-Ⅰ）were evaluated.Compared with the control group,mitochondria and[Ca2＋]iin group with Ca were increased,and endocytoplasmic reticulum in group with Ca was broadened,the fluorescence diffusion length of GJIC in group with Ca was diminution at 2day.Compared with the control group,2day incubation later,total protein in group with 1,4mmol/L Ca was higher（P0.05or P0.01）,Col-Ⅰin group with Ca was inhibited（P0.01）its secretion.5,8day incubation later,Col-Ⅰin group with Ca was enhanced（P0.05or P0.01）,and total protein was lower（P0.05or P0.01）only at 8 day.In conclusion,2day incubation later,Ca enhanced OB metabolism,[Ca2＋]I deposition,total protein secretion,and inhibited GJIC and Col-Ⅰsecretion,and benefited cell proliferation.After multiplication period,Ca inhibited total protein secretion,promoted Col-Ⅰsecretion,enhanced OB matrix maturation,benefited bony remodeling.