Geriatric Anaesthesia Research Unit, Department of Anaesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, 149 13th St., Room 4310, Charlestown, MA 02129-2060, USA Department of Anaesthesiology, Tianjin Medical University General Hospital, Tianjin Research Institute of Anaesthesiology, Tianjin 300052, PR China.
Geriatric Anaesthesia Research Unit, Department of Anaesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, 149 13th St., Room 4310, Charlestown, MA 02129-2060, USA.
Br J Anaesth. 2014 Oct;113(4):695-707. doi: 10.1093/bja/aeu053. Epub 2014 Apr 3.
Isoflurane has been reported to induce caspase-3 activation, which may induce neurotoxicity and contribute to the pathogenesis of Alzheimer's disease. However, the underlying mechanism is largely unknown, especially whether or not isoflurane can induce ryanodine receptors (RyRs)-associated endoplasmic reticulum (ER) stress, leading to caspase-3 activation. We therefore assessed the effects of isoflurane on RyRs-associated ER stress.
We treated primary neurones from wild-type (C57BL/6J) mice with 1% and 2% isoflurane for 1, 3, or 6 h. We then measured levels of C/EBP homologous protein (CHOP) and caspase-12, two ER stress markers, using immunocytochemistry staining and western blotting analysis. Dantrolene (5 μM), the antagonist of RyRs, was used to investigate the role of RyRs in the isoflurane-induced ER stress and caspase-3 activation.
Isoflurane 2% for 6 h treatment increased the levels of CHOP (876% vs 100%, P=0.00009) and caspase-12 (276% vs 100%, P=0.006), and induced caspase-3 activation in the neurones. The administration of 2% isoflurane for 3 h (shorter duration), however, only increased the levels of CHOP (309% vs 100%, P=0.003) and caspase-12 (266% vs 100%, P=0.001), without causing caspase-3 activation. The isoflurane-induced ER stress (CHOP: F=16.64, P=0.0022; caspase-12: F=6.13, P=0.0383) and caspase-3 activation (F=32.06, P=0.0005) were attenuated by the dantrolene treatment.
These data imply that isoflurane might induce caspase-3 activation by causing ER stress through RyRs, and dantrolene could attenuate the isoflurane-induced ER stress and caspase-3 activation. Further investigations of the potential neurotoxicity of isoflurane are needed.
已有报道称异氟醚可诱导半胱天冬酶-3 激活，这可能诱导神经毒性并导致阿尔茨海默病的发病机制。然而，其潜在机制在很大程度上尚不清楚，特别是异氟醚是否能诱导肌浆网（RyRs）相关内质网（ER）应激，导致半胱天冬酶-3 激活。因此，我们评估了异氟醚对 RyRs 相关 ER 应激的影响。
我们用 1%和 2%的异氟醚处理野生型（C57BL/6J）小鼠的原代神经元 1、3 或 6 小时。然后，我们使用免疫细胞化学染色和 Western blot 分析来测量 C/EBP 同源蛋白（CHOP）和半胱天冬酶-12 这两种 ER 应激标志物的水平。使用肌浆网受体拮抗剂丹曲林（5 μM）来研究 RyRs 在异氟醚诱导的 ER 应激和半胱天冬酶-3 激活中的作用。
2%异氟醚处理 6 小时增加了 CHOP（876%比 100%，P=0.00009）和半胱天冬酶-12（276%比 100%，P=0.006）的水平，并诱导神经元中半胱天冬酶-3 的激活。然而，用 2%异氟醚处理 3 小时（持续时间较短）仅增加了 CHOP（309%比 100%，P=0.003）和半胱天冬酶-12（266%比 100%，P=0.001）的水平，而没有引起半胱天冬酶-3 的激活。丹曲林处理可减轻异氟醚诱导的 ER 应激（CHOP：F=16.64，P=0.0022；半胱天冬酶-12：F=6.13，P=0.0383）和半胱天冬酶-3 的激活（F=32.06，P=0.0005）。
这些数据表明，异氟醚可能通过肌浆网受体引起 ER 应激，从而诱导半胱天冬酶-3 激活，丹曲林可减轻异氟醚诱导的 ER 应激和半胱天冬酶-3 激活。需要进一步研究异氟醚的潜在神经毒性。
