辐照骨髓淋巴细胞对成骨细胞的影响

探索辐照后骨髓淋巴细胞对成骨细胞增殖分化的影响。采用酶消化法分离培养新生SD大鼠头盖骨成骨细胞,密度梯度离心法获取大鼠骨髓淋巴系细胞,137Csγ-射线辐照淋巴细胞和成骨细胞,剂量6 Gy,分组为0 Gy成骨细胞+0 Gy淋巴细胞(0OB0L),0 Gy成骨细胞+6 Gy淋巴细胞(0OB6L),6 Gy成骨细胞+6 Gy淋巴细胞(6OB6L),共培养6 h后,取各组淋巴细胞与正常成骨细胞共培养,MTT和PNPP法观察其对成骨细胞增殖和分化的影响,Real time PCR方法观察成骨细胞ALP、OCN、RANKL和OPG的基因表达变化。结果显示,辐照骨髓淋巴细胞抑制成骨细胞分化,成骨细胞ALP和OCN的表达显著降低,RANKL的表达增高,RANKL/OPG的比值则显著升高。辐照后的骨髓淋巴细胞抑制成骨细胞分化并且可能通过改变RANKL/OPG的比值进而影响破骨细胞的功能。

Effects of radiated lymphocyte on the osteoblast

The osteoblast was cultured from cranium of fetal rat with enzymatic digestion method; bone marrow lymphocyte was cultured by density gradient centrifugation; two kinds of cells were irradiated with 137Cs γ-rays of 6 Gy; the groups were set as 0 Gy osteoblast＋0 Gy lymphocyte（0OBOL）, 0 Gy osteoblast＋6 Gy lymphocyte（0OB6L）, and 6 Gy osteoblast＋6 Gy lymphocyte（6OB6L）. After 6 h co-cultivation, the lymphocyte was co-cultured with normal osteoblast, and then the proliferation and differentiation of osteoblasts were detected by MTT and PNPP after 72 h, meanwhile, the mRNA expression of ALP, OCN, RANKL, and OPG of the osteoblast were detected after 2 h. The results suggest that radiated lymphocyte can inhibit the differentiation of osteoblast, down-regulate the mRNA expression of ALP and OCN, up-regulate the mRNA expression of RANKL and increase the ratio of RANKL/OPG. The radiated bone marrow lymphocyte not only suppresses the differentiation of osteoblast, but also affects the osteoclast by changing the ratio of RANKL/OPG.