Department of Anesthesiology, Affiliated Hospital of Hebei University, Baoding, China.
Eur Rev Med Pharmacol Sci. 2019 Jan;23(1):370-377. doi: 10.26355/eurrev_201901_16785.
This research aims to investigate the role and mechanism of PI3K/Akt pathway in the pathological process of lung ischemia-reperfusion injury in dexmedetomidine-treated rats.
Forty-five healthy male Sprague-Dawley rats were divided into three groups: sham operation group, lung ischemia-reperfusion group (IR group) and dexmedetomidine pretreatment group (Dex group). Rats in the sham operation group did not receive other procedures except for opening left chest. The left lung hilar of rats in the IR group was clamped with non-invasive vascular clamp after anesthesia to establish an ischemic model. After 1 hour, the vascular clamp was released and the rats were reperfused for 2 hours. As for rats in the Dex group, 3 μg/kg of dexmedetomidine (pumping time of 10 min) was pumped through the tail vein before releasing the left hilar clamp. After the experiment, blood samples and lung tissues were collected. Serum levels of interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), IL-10, and IL-1 in rats were examined. Activities of malondialdehyde (MDA), myeloperoxidase (MPO), superoxide dismutase (SOD) and catalase (CAT) in rat lung tissues were also detected. Besides, the expressions of hypoxia-inducible factor-la (HIF-la), p-Akt, Caspase-3, and Caspase-9 in lung tissues were detected by Western blot. The mRNA expression levels of HIF-1a, p-Akt, Caspase-3, and Caspase-9 in lung tissues were evaluated by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR).
Lung ischemia-reperfusion markedly increased the levels of IL-6, TNF-α, IL-10, and IL-1 in the IR group. In contrast, dexmedetomidine pretreatment decreased the expression levels of IL-6, TNF-α, IL-10, and IL-1in the Dex group. Also, the activities of MDA and MPO in lung tissues of rats in the IR group significantly increased after lung ischemia-reperfusion injury, whereas dexmedetomidine pretreatment reversed the elevated activities of MDA and MPO in the Dex group. Furthermore, dexmedetomidine pretreatment also improved the activities of SOD and CAT in rat lung tissues compared with rats with lung ischemia-reperfusion injury. In addition, dexmedetomidine pretreatment increased the expression levels of HIF-1α, p-Akt and HIF- in the Dex group when compared to those in the IR group. The mRNA expressions of HIF-1a, p-Akt, Caspase-3, and Caspase-9 in lung tissue of rats was significantly reduced after dexmedetomidine pretreatment.
Rat lung ischemia-reperfusion can induce severe lung injury. Dexmedetomidine treatment can attenuate lung ischemia-reperfusion injury by activating the PI3K/Akt signaling pathway at the transcriptional level.
本研究旨在探讨 PI3K/Akt 通路在右美托咪定预处理大鼠肺缺血再灌注损伤病理过程中的作用及机制。
45 只健康雄性 Sprague-Dawley 大鼠随机分为三组：假手术组、肺缺血再灌注组（IR 组）和右美托咪定预处理组（Dex 组）。假手术组大鼠除开胸外，不进行其他操作。IR 组大鼠麻醉后用无创血管夹夹闭左肺门，建立缺血模型。1 小时后，松开血管夹，再灌注 2 小时。Dex 组大鼠在松开左肺门夹前，经尾静脉泵入 3μg/kg 右美托咪定（泵注时间 10 min）。实验结束后，采集血样和肺组织。检测大鼠血清白细胞介素 6（IL-6）、肿瘤坏死因子-α（TNF-α）、IL-10、IL-1 水平。检测大鼠肺组织丙二醛（MDA）、髓过氧化物酶（MPO）、超氧化物歧化酶（SOD）和过氧化氢酶（CAT）的活性。采用 Western blot 法检测肺组织缺氧诱导因子-1α（HIF-1α）、磷酸化 Akt（p-Akt）、半胱氨酸天冬氨酸蛋白酶-3（Caspase-3）和半胱氨酸天冬氨酸蛋白酶-9（Caspase-9）的表达。采用实时荧光定量聚合酶链反应（qRT-PCR）法检测肺组织 HIF-1α、p-Akt、Caspase-3 和 Caspase-9 的 mRNA 表达水平。
肺缺血再灌注明显增加了 IR 组大鼠血清中 IL-6、TNF-α、IL-10 和 IL-1 的水平。相比之下，右美托咪定预处理降低了 Dex 组大鼠血清中 IL-6、TNF-α、IL-10 和 IL-1 的表达水平。此外，肺缺血再灌注损伤后大鼠肺组织中 MDA 和 MPO 的活性明显升高，而右美托咪定预处理逆转了 Dex 组 MDA 和 MPO 活性的升高。此外，与肺缺血再灌注损伤大鼠相比，右美托咪定预处理还改善了大鼠肺组织中 SOD 和 CAT 的活性。此外，与 IR 组相比，右美托咪定预处理增加了 Dex 组 HIF-1α、p-Akt 和 HIF-的表达水平。右美托咪定预处理后，大鼠肺组织中 HIF-1α、p-Akt、Caspase-3 和 Caspase-9 的 mRNA 表达明显减少。
大鼠肺缺血再灌注可引起严重肺损伤。右美托咪定通过激活 PI3K/Akt 信号通路在转录水平上减轻肺缺血再灌注损伤。
