辐射对体外培养的小鼠成骨细胞Ⅰ型胶原mRNA表达的影响

Effect of radiation on collagen type I mRNA expressions in mouse osteoblast in vitro

目的肿瘤放射治疗诱发骨组织损伤，辐射后成骨细胞Ⅰ型胶原的基因表达分析揭示辐射对早期和晚期的成骨细胞功能的影响。方法在体外诱导骨髓基质细胞生成成骨细胞，对其特性进行确定。用聚合酶链式反应（PCR）方法分析了1-4Gv照射的早期和晚期成骨细胞的Ⅰ型胶原表达。结果与对照组相比，经1～3Gy剂量照射后的早期成骨细胞Ⅰ型胶原的表达增强（P〈0．05），但随后即培养10d后的晚期成骨细胞Ⅰ型胶原的表达降低；而在4Gy剂量照射下，晚期成骨细胞Ⅰ型胶原的表达明显高于早期成骨细胞的表达（P〈0．01）。结论在1-3Gy辐射后，早期成骨细胞Ⅰ型胶原的表达增强，成骨能力增强；晚期成骨细胞I型胶原的表达降低，成骨能力减弱。而4Gy辐射后，晚期成骨细胞Ⅰ型胶原的表达增强，有可能是其代偿功能表现。

Objective Cancer radio-therapy may induce bone damage of the patients, collagen type I gene expressions in osteoblast after radiation indicates the influence of radiation on the function of early and late osteoblast. Methods Bone marrow stromal cells were differentiated into osteoblasts in vitro, and the characteristics was indentified. The collagen type I expressions in early and late stage osteoblasts exposed to 1-4 Gy radiation were examined by RT-PCR. Results Compared to control group, collagen type I gene expressions increased in early osteoblast after 1-3 Gy radiation （P〈0.05）, while the gene expressions in late osteoblast that cultured 10 days decreased. Collagen type I gene expression in late stage ostoblast after 4 Gy irradiation was greatly higher than that in early stage osteoblast （P〈0.01）. Conclusion After 1-3 Gy irradiation, the collagen type I expression in early osteoblast was enhanced, indicating the increased ability of bone formation. The exposure to 1-3 Gy decreased collagen type I expression in late osteoblast and weakened the ability of bone formation. The result of high expression of collagen type I in late osteoblast after 4 Gy irradiation may be the manifestation of compensatory function.