为了探讨氟化物对反刍动物成骨细胞的细胞周期和凋亡的影响,本研究以初生山羊股骨骨膜为材料分离成骨细胞,接种于含15%FBS的DMEM培养液,于37℃、5%CO2的培养箱中培养。通过形态观察(Hoechst33342/PI双重染色)、DNA ladder电泳、透射电镜、流式细胞仪等方法检测氟对成骨细胞的调控作用。结果表明,高氟(1.0×10^-3及2.5×10^-3mol/L)使成骨细胞G0/G1期减少,S期细胞增多,抑制成骨细胞周期由合成DNA的S期向G2M期转化,使细胞停滞在S期。1.0×10^-5-2.5×10^-3mol/L氟可使DNA断裂,诱导成骨细胞凋亡,其中1.0×10^-4mol/L氟所致早期和晚期凋亡率最高,分别为3.33%和2.92%。本试验证实氟可诱导成骨细胞凋亡。
In order to determine whether fluoride would induce apoptotic cell death, our research group monitored DNA fragmentation and the cellular morphology with Hoechst33342/PI double staining,DNA ladder and transmission electron microscope (TEM). The level of apoptosis was analyzed with a fluorescence-activated cell sorter (FACS) by the Annexin-V-FITC and the propidium iodine (PI) double staining method. Cell-cycle analysis was also examined with FACS using PI staining. The experimental results were as follows: Ultrastructural features of osteoblasts in control group exhibited clear nuclear envelope, large nucleolus, even karyoplasms, abundant endoplasmic reticulum and mitochondria. When fluoride was more than 1.0 × 10^-4 mol/L, cellular membrane disintegration, cytoplasm condensation, chromatin compaction or fragmentation, endoplasmic reticulum (ER) expansion, nucleus shrinkage or periphery were observed. Fluoride at 1.0 × 10^-5 - 2.5 × 10^-3 mol/L induced apoptosis with DNA fragmentation. FACS cell-cycle analysis demonstrated that fluoride caused potent G0/G1 arrest. Few cells could be found either in the S phases or the G2/M, thus inhibiting the transformation from S phase into G2/M phase under high levels of fluoride. The highest apoptosis rate of earlier and later stages were induced by 1.0× 10^-4 mol/L fluoride(3.33% and 2. 92% respectively). In conclusion, the results revealed that fluoride can induce apoptosis in osteoblast.