金属铬离子及抗氧化剂N-乙酰半胱氨酸对人成骨样细胞MG63形态学的影响

Effect of Chromium Ion and Antioxidant N-acetyl-cysteine on Morphology of Human Osteoblast-like MG63 Cell Line

目的研究金属铬离子(Cr6+)对人成骨样细胞MG63形态学的影响以及抗氧化剂N-乙酰半胱氨酸(NAC)对Cr6+作用的拮抗效应。方法分别用含5μmol/LCr6+、10μmol/LCr6+、20μmol/LCr6+、2mmol/LNAC以及2mmol/LNAC+10μmol/LCr6+的F12培养基培养人成骨样细胞MG6324h。其中,2mmol/LNAC+10μmol/LCr6+组为2mmol/LNAC预处理细胞30min后再用含10μmol/LCr6+的F12培养基继续培养24h。另设空白对照组,即用不含Cr6+和NAC的F12培养基培养MG63细胞。倒置相差显微镜和透射电镜分别观察各组细胞形态和细胞超微结构的改变。结果低浓度Cr6+处理组(5μmol/LCr6+)MG63细胞伪足回缩,细胞间隙增大,细胞线粒体肿胀,粗面内质网扩张,胞浆出现少量空泡;随着Cr6+浓度的增高(10μmol/LCr6+),细胞逐渐变圆,脱壁,细胞内出现大量空泡,细胞核异形性大,染色质固缩,出现假包涵体;高浓度Cr6+处理组(20μmol/LCr6+)MG63细胞大部分脱壁,细胞超微结构改变更明显,胞膜不完整,细胞出现崩解,可见细胞碎片;NAC单独处理组与NAC+Cr6+处理组细胞形态结构与对照组相比均无明显改变。结论Cr6+对人成骨样细胞MG63形态结构有明显的破坏,且随着Cr6+浓度的增高,破坏程度加剧;NAC可抑制Cr6+引起的MG63细胞形态学改变。

Objective The objective of this study was to evaluate the cellular morphology and ultrastructural changes of MG63 cell line exposed to salt solutions of hexavalent chromium ions which may be released from the alloys used in biomedicine, and to determine if antioxidant N-acetyl-cysteine （NAC） could reduce the cytotoxicity induced by chromium ion. Methods MG63 cell lines were exposed respectively to 5 μmol/L Cr^6＋ , 10 μmol/L Cr^6＋, 20 μmol/L Cr^6＋ or 2 mmol/L NAC F12 medium in vitro for 24 h. And also, in order to assess the ability of antioxidant NAC to protect MG63 against chromium ion-induced cellular morphology and ultrastructural changes, MG63 were preincubated with 2 mmol/L NAC for 30 rain, and then cultured with 10 μmol/L Cr^6＋ F12 medium for further 24 h. The cellular morphology and ultrastructural features were examined by optical microscopy and transmission electron microscopy （TEM）. Results Under optical microscopy, we found that MG63 cells became round and detached from the culture dishes when exposed to chromium ions. The TEM examination confirmed these optical microscopic findings. MG63 cells treated with Cr^6＋ had the irregular shaped nuclei, swollen mitochondria, dilation of rER and numerous large vacuoles in the cytoplasm. These cellular morphology and ultrastructural changes of MG63 cell line were noticeably reduced by the NAC （2mmol/L） pretreatment. Conclusion Cr^6＋ significantly destroyed the cellular morphology and ultrastructure of MG63 cell line. Antioxidant N-acetyl-cysteine can play a critical role against Cr^6＋-induced cell changes.