From the Geriatric Anesthesia Research Unit, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129-2060; the Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129-2060; the Department of Anatomy and Neurobiology, Xuzhou Medical College, Xuzhou 221002, China.
From the Geriatric Anesthesia Research Unit, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129-2060; the Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129-2060.
J Biol Chem. 2010 Feb 5;285(6):4025-4037. doi: 10.1074/jbc.M109.065664. Epub 2009 Dec 10.
The common inhalation anesthetic isoflurane has been shown to induce apoptosis, which then leads to accumulation of beta-amyloid protein, the hallmark feature of Alzheimer disease neuropathogenesis. The underlying molecular mechanism of the isoflurane-induced apoptosis is largely unknown. We, therefore, set out to assess whether isoflurane can induce apoptosis by regulating Bcl-2 family proteins, enhancing reactive oxygen species (ROS) accumulation, and activating the mitochondrial pathway of apoptosis. We performed these studies in cultured cells, primary neurons, and mice. Here we show for the first time that treatment with 2% isoflurane for 6 h can increase pro-apoptotic factor Bax levels, decrease anti-apoptotic factor Bcl-2 levels, increase ROS accumulation, facilitate cytochrome c release from the mitochondria to the cytosol, induce activation of caspase-9 and caspase-3, and finally cause apoptosis as compared with the control condition. We have further found that isoflurane can increase the mRNA levels of Bax and reduce the mRNA levels of Bcl-2. The isoflurane-induced ROS accumulation can be attenuated by the intracellular calcium chelator BAPTA. Finally, the anesthetic desflurane does not induce activation of mitochondrial pathway of apoptosis. These results suggest that isoflurane may induce apoptosis through Bcl-2 family proteins- and ROS-associated mitochondrial pathway of apoptosis. These findings, which have identified at least partially the molecular mechanism by which isoflurane induces apoptosis, will promote more studies aimed at studying the potential neurotoxic effects of anesthetics.
常用吸入麻醉剂异氟烷已被证明可诱导细胞凋亡，进而导致β淀粉样蛋白的积累，这是阿尔茨海默病神经病变的标志性特征。异氟烷诱导细胞凋亡的潜在分子机制在很大程度上尚不清楚。因此，我们着手评估异氟烷是否可以通过调节 Bcl-2 家族蛋白、增加活性氧 (ROS) 积累以及激活细胞凋亡的线粒体途径来诱导细胞凋亡。我们在培养的细胞、原代神经元和小鼠中进行了这些研究。在这里，我们首次表明，用 2%异氟烷处理 6 小时可增加促凋亡因子 Bax 的水平，降低抗凋亡因子 Bcl-2 的水平，增加 ROS 积累，促进细胞色素 c 从线粒体释放到细胞质，诱导 caspase-9 和 caspase-3 的激活，最终与对照条件相比导致细胞凋亡。我们还发现异氟烷可以增加 Bax 的 mRNA 水平并降低 Bcl-2 的 mRNA 水平。细胞内钙螯合剂 BAPTA 可减轻异氟烷诱导的 ROS 积累。最后，麻醉剂地氟烷不会诱导线粒体细胞凋亡途径的激活。这些结果表明，异氟烷可能通过 Bcl-2 家族蛋白和 ROS 相关的线粒体细胞凋亡途径诱导细胞凋亡。这些发现至少部分确定了异氟烷诱导细胞凋亡的分子机制，将促进更多旨在研究麻醉剂潜在神经毒性作用的研究。
