摘要
目的 观察胰岛素样生长因子Ⅰ（IGF-Ⅰ）对体外培养的大鼠成骨细胞的增殖、凋亡及Ⅰ型胶原蛋白合成的影响，探讨IGF-Ⅰ对骨代谢影响的可能机制。方法 不同浓度rhIGF-Ⅰ刺激体外培养的大鼠成骨细胞，采用噻唑蓝（MTT）法测定细胞增殖能力；肿瘤坏死因子α（TNF-α单独或与rhIGF-Ⅰ共同刺激成骨细胞，流式细胞仪检测细胞周期和凋亡率；rhIGF-Ⅰ刺激成骨细胞，免疫细胞化学结合计算机图像分析系统检测Ⅰ型胶原蛋白的表达。结果 一定浓度IGF-Ⅰ能明显增加成骨细胞数量（P〈0．05），在0．1～100ng／ml这种作用与IGF-Ⅰ的浓度呈正相关；TNF-α在0．1～100ng/ml浓度范围内呈剂量依赖性地促进成骨细胞凋亡（P〈0．05），并使S期细胞减少（P〈0．05），而IGF-Ⅰ能抑制，TNF-α对成骨细胞的促凋亡作用（P〈0．05）；经IGF-Ⅰ的刺激，成骨细胞Ⅰ型胶原蛋白的表达明显高于对照组（P〈0．05）。结论 IGF-Ⅰ对大鼠成骨细胞有明显的促增殖作用，在0．1～100ng/ml之间呈浓度依赖性，IGF-Ⅰ能抑制，TNF-α诱导的大鼠成骨细胞凋亡，IGF-Ⅰ能促进大鼠成骨细胞Ⅰ型胶原蛋白的合成。
Objective To investigate the effect of rhIGF-Ⅰ on the proliferation, apoptosis and type Ⅰ collagen synthesis of rat osteoblasts in vitro. Methods Rat calvaria cells were cultured in medium with or without IGF-Ⅰ and TNF-α was added in the medium to increase apoptosis. Cell proliferatin was assessed by MTT colorimetric assay;cell cycle and apoptosis were analysed by flow cytometry; type Ⅰ collagen expression was determined by immunocytochemistry and computer image anylysis system. Results The OD of formazan, which reflects the cell number,significantly increased in osteoblasts exposed to IGF-Ⅰ at 10-100 ng/ml for 24 hrs and 0.1-100 ng/ml for 48 and 72 hrs compared with those exposed to vehicle medium（ P 〈 0.05-0.01 ） .TNF-α increased the cell apoptosis in a dose-dependent manner（ P 〈 0.001-0.05） ,increased the number of cells in G0/G1 phase（ P 〈 0.05-0.01 ） and decreased the number in S phase（ P 〈 0.05）. IGF-Ⅰ inhibited the effect of TNF-α on apoptosis. The expression of type Ⅰ collagen in IGF-Ⅰ-treated cells was higher than that in vehicle-treated cells（ P 〈 0.05）. Conclusions IGF- Ⅰ stimulates The cell proliferation of osteoblast,inhibitits apoptosis induced by TNF-α and increase the synthesis of type Ⅰ collagen in vitro .Thus IGF-Ⅰ probably promote bone formation in vitro.
出处
《中国骨质疏松杂志》
CAS
CSCD
2006年第1期17-21,共5页
Chinese Journal of Osteoporosis
