Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan.
Toxicol In Vitro. 2012 Sep;26(6):862-71. doi: 10.1016/j.tiv.2012.04.024. Epub 2012 May 1.
This study examined whether propofol altered Ca(2+) and caused cell death in DBTRG-05MG cells. Propofol at 400-1000μM increased Ca(2+) in a concentration-dependent manner. The signal was decreased partially by removal of extracellular Ca(2+). Propofol-induced Ca(2+) influx was not altered by nifedipine, econazole, SK&F96365, and protein kinase C (PKC) activators; but was inhibited by PKC inhibitor. In Ca(2+)-free medium, pretreatment with the endoplasmic reticulum Ca(2+) pump inhibitors thapsigargin or 2,5-di-tert-butylhydroquinone (BHQ) nearly abolished propofol-induced Ca(2+) rise. Incubation with propofol inhibited thapsigargin or BHQ-induced Ca(2+) rise. Inhibition of phospholipase C (PLC) with U73122 abolished propofol-induced Ca(2+) rise. At 300-700μM, propofol killed cells in a concentration-dependent manner. The cytotoxic effect of propofol was partly reversed by prechelating cytosolic Ca(2+) with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA). Annexin V/PI staining further showed that 300-500μM propofol evoked apoptosis. Propofol also increased reactive oxygen species (ROS) production. Overall, propofol induced a Ca(2+) rise by inducing PLC- and PKC-dependent Ca(2+) release from the endoplasmic reticulum and Ca(2+) entry via non store-operated Ca(2+) channels. Propofol induced cell death that might involve ROS-mediated apoptosis.
本研究旨在探讨丙泊酚是否会改变Ca(2+)并导致 DBTRG-05MG 细胞死亡。丙泊酚在 400-1000μM 浓度范围内呈浓度依赖性增加Ca(2+)。去除细胞外 Ca(2+)可部分降低该信号。硝苯地平、依康唑、SK&F96365 和蛋白激酶 C（PKC）激活剂均不能改变丙泊酚诱导的 Ca(2+)内流，但 PKC 抑制剂可抑制该内流。在无 Ca(2+)培养基中，内质网 Ca(2+)泵抑制剂 thapsigargin 或 2,5-二叔丁基对苯二酚（BHQ）预处理几乎可完全消除丙泊酚诱导的Ca(2+)升高。孵育丙泊酚可抑制 thapsigargin 或 BHQ 诱导的Ca(2+)升高。用 U73122 抑制磷脂酶 C（PLC）可消除丙泊酚诱导的Ca(2+)升高。在 300-700μM 范围内，丙泊酚呈浓度依赖性杀伤细胞。丙泊酚的细胞毒性作用可部分被 1,2-双（2-氨基苯氧基）乙烷-N,N,N',N'-四乙酸（BAPTA）螯合胞质 Ca(2+)逆转。 Annexin V/PI 染色进一步表明，300-500μM 丙泊酚可诱导细胞凋亡。丙泊酚还增加活性氧物质（ROS）的产生。总的来说，丙泊酚通过诱导 PLC 和 PKC 依赖性内质网 Ca(2+)释放以及非储存操纵性 Ca(2+)通道的 Ca(2+)内流引起Ca(2+)升高。丙泊酚诱导的细胞死亡可能涉及 ROS 介导的凋亡。
