Department of Neurosurgery, The Fourth College Hospital of Harbin Medical University, Harbin, PR China.
Int J Radiat Biol. 2011 Oct;87(10):1061-6. doi: 10.3109/09553002.2011.584938.
Our aim was to study calcium overload-induced apoptosis and its relation to reactive oxygen species (ROS) in rat C6 glioma cells after sonodynamic treatment (SDT).
Hematoporphyrin monomethyl ether (HMME) was used as the sonosensitizer. The concentration of intracellular Ca(2+) (Ca(2+)) was measured by fluorometry. Apoptosis and necrosis rates were evaluated by a flow cytometry. Moreover, sarcoplasmic reticulum Ca(2+) -ATPase (SERCA(2)), cytochrome c (cyto-c) and cleaved caspase-3 were investigated by immunoblotting.
Our study indicated that Ca(2 +) and ROS increased in cells of SDT group, the apoptosis rate, quantity of cyto-c and cleaved caspase-3 markedly increased after SDT. Furthermore, N-Acetyl-L-cysteine (NAC) or 1,2-bisethane-N,N,N',N'-tetraacetic acid tetrakis ester (BAPTA-AM) could decrease the apoptosis rate, the release of cyto-c and cleaved caspase-3 in SDT group, SERCA(2) degradation was found in SDT group and could also be prevented by the addition of NAC.
Our results show that HMME-SDT can induce C6 cell death through both necrosis and apoptosis. ROS in C6 cells play a decisive role in HMME-SDT-induced cell death. The endoplasmic reticulum (ER) may be a major target of HMME-SDT, ROS can induce SERCA(2) degradation, causing the elevation of Ca(2+).
本研究旨在探讨声动力学治疗（SDT）后大鼠 C6 神经胶质瘤细胞内钙超载诱导的细胞凋亡及其与活性氧（ROS）的关系。
血卟啉单甲醚（HMME）为声敏剂。采用荧光法测定细胞内钙离子浓度(Ca2+)。用流式细胞术检测细胞凋亡和坏死率。此外，通过免疫印迹法检测肌浆网 Ca2+-ATP 酶（SERCA（2））、细胞色素 c（cyto-c）和裂解 caspase-3。
研究表明，SDT 组细胞Ca2+和 ROS 增加，SDT 后细胞凋亡率、cyto-c 和裂解 caspase-3 明显增加。此外，N-乙酰-L-半胱氨酸（NAC）或 1,2-双乙胺-N,N,N',N'-四乙酸四甲酯（BAPTA-AM）可降低 SDT 组的凋亡率、cyto-c 和裂解 caspase-3 的释放，SDT 组发现 SERCA（2）降解，加入 NAC 可预防其降解。
我们的结果表明，HMME-SDT 可通过坏死和凋亡诱导 C6 细胞死亡。C6 细胞中的 ROS 在 HMME-SDT 诱导的细胞死亡中起决定性作用。内质网（ER）可能是 HMME-SDT 的主要靶点，ROS 可诱导 SERCA（2）降解，导致Ca2+升高。
