Department of Environmental Epidemiology and Bone Toxicology, Institute of Radiation Medicine, Fudan University, China.
Environ Toxicol Pharmacol. 2012 Mar;33(2):149-57. doi: 10.1016/j.etap.2011.12.009. Epub 2011 Dec 13.
The combined effects of γ-irradiation and cadmium (Cd) exposures on osteoblasts were observed in the present study. Osteoblasts were exposed to γ-irradiation (0.5 Gy) and Cd (0-0.5 μmol/L). Cell viability, alkaline phosphatase (ALP) activity, mineralization ability, cell apoptosis and genes expression of ALP, osteocalcin (OC) and caspase 3 were observed. Low concentrations of Cd exposure had no obvious influence on cell viability, ALP activity and apoptosis. However, low levels of Cd exposure combined with γ-irradiation induced more toxic effects on osteoblasts than those treated with Cd or irradiation alone. High concentrations of Cd combined with irradiation exposure induced more significant inhibition in cell viability, ALP activity and mineralization ability than those exposed to Cd or irradiation alone. Meanwhile, OC and ALP mRNA expression of cells treated with Cd combined with irradiation were down-regulated more significantly than those treated with Cd or irradiation alone. Cd combined with γ-irradiation could obviously enhance osteoblast apoptosis and up-regulated caspase 3 mRNA expression compared with those treated with Cd or irradiation alone. This study indicated that ionizing irradiation can enhance Cd toxic effects on osteoblast viability and differentiation and apoptosis may play an important role in this progress.
本研究观察了γ 射线辐射和镉（Cd）暴露对成骨细胞的联合效应。将成骨细胞暴露于γ 射线辐射（0.5Gy）和 Cd（0-0.5μmol/L）。观察细胞活力、碱性磷酸酶（ALP）活性、矿化能力、细胞凋亡以及 ALP、骨钙素（OC）和半胱氨酸天冬氨酸蛋白酶 3 基因的表达。低浓度 Cd 暴露对细胞活力、ALP 活性和凋亡没有明显影响。然而，低水平的 Cd 暴露与 γ 射线辐射联合作用对成骨细胞的毒性作用比单独用 Cd 或辐射处理更为明显。高浓度 Cd 与照射联合暴露对细胞活力、ALP 活性和矿化能力的抑制作用比单独用 Cd 或照射更为显著。同时，与单独用 Cd 或辐射处理相比，Cd 与照射联合处理的细胞中 OC 和 ALP mRNA 的表达明显下调。与单独用 Cd 或辐射处理相比，γ 射线辐射与 Cd 联合作用可明显增强成骨细胞凋亡，并上调 caspase 3 mRNA 表达。本研究表明，电离辐射可增强 Cd 对成骨细胞活力、分化和凋亡的毒性作用，凋亡可能在此过程中起重要作用。
