去甲汉黄芩素通过激活Nrf2/HO-1信号通路缓解急性低压低氧诱导肺组织损伤的作用研究

Effect of norwogonin in alleviating acute hypobaric hypoxia induced lung tissue injury by activating Nrf2/HO-1 signaling pathway

关键词:  去甲汉黄芩素  急性低压低氧  肺损伤  氧化应激  Nrf2/HO-1信号通路

Key words:  norwogonin  acute hypobaric hypoxia  lung injury  oxidative stress  Nrf2/HO-1 signaling pathway

摘要:

目的 研究去甲汉黄芩素改善急性低压低氧(AHH)诱导小鼠肺组织损伤的作用与潜在机制。方法 78只雄性BALB/c小鼠随机分为6组。正常对照组和急性低压低氧组小鼠腹腔注射生理盐水，4组给药组分别腹腔注射芦丁(200 mg/kg)和低、中、高剂量去甲汉黄芩素(50 mg/kg，100 mg/kg、200 mg/kg)。将小鼠置于模拟海拔8 000 m暴露24 h构建AHH肺损伤模型。HE染色观察肺组织病理变化；试剂盒检测肺组织中过氧化氢(H2O2)、丙二醛(MDA)、超氧化物歧化酶(SOD)和谷胱甘肽(GSH)的水平以及肿瘤坏死因子α(TNF-α)、白细胞介素1β(IL-1β)和白细胞介素6(IL-6)的含量；Western blot检测肺组织中缺氧相关蛋白[缺氧诱导因子-1α(HIF-1α)和血管内皮生长因子(VEGF)]、抗氧化应激相关蛋白[核因子-E2相关因子2(Nrf2)和血红素加氧酶-1(HO-1)]、炎性相关蛋白[(核因子κB(NF-κB)和TNF-α)]以及凋亡相关蛋白[Bcl-2关联X蛋白(Bax)、B淋巴细胞瘤-2(Bcl-2)和裂解的半胱氨酸-天冬氨酸蛋白酶-3(Cleaved caspase3)]的表达水平；Autodock软件进行分子对接。结果 与急性低压低氧组相比，去甲汉黄芩素预处理能显著减少肺组织含水量和病理学变化，降低肺组织中H2O2、MDA、IL-1β、TNF-α和IL-6的含量，升高SOD活力和GSH水平，下调HIF-1α、VEGF、Nrf2、HO-1、NF-κB、TNF-α、Bax和Cleaved caspase3蛋白表达，上调Bcl-2蛋白表达，减少Bax/Bcl-2的比值。分子对接结果显示去甲汉黄芩素与Nrf2、HO-1表现出良好的结合能力。结论 去甲汉黄芩素通过激活Nrf2/HO-1信号通路缓解氧化应激、减少炎性反应和抑制细胞凋亡，从而改善急性低压低氧诱导的小鼠肺组织损伤。

Abstract:

OBJECTIVE The protective effect and associated mechanisms of norwogonin against acute hypobaric hypoxia induced lung tissue injury were explored. METHODS Seventy-eight male BALB/c mice were randomly divided into 6 groups. Mice in the normal control group and the acute hypobaric hypoxia group were intraperitoneally injected with normal saline, and the administration groups were intraperitoneally injected with rutin (200 mg/kg) and low, medium, and high doses of norwogonin (50 mg/kg, 100 mg/kg, 200 mg/kg). The mice model of acute hypobaric hypoxia lung injury was established by exposure to an altitude of 8000 m for 24 h. Pathological changes in mice lungs were evaluated using H&E staining. The levels of H2O2, MDA, SOD, and GSH and the contents of IL-1β, TNF-α, and IL-6 in lung tissue were detected by using commercial kits. The levels of hypoxia-related proteins (HIF-1α and VEGF), antioxidative stress-related proteins (Nrf2 and HO-1), inflammation-related proteins (NF-κB and TNF-α), and apoptosis-related proteins (Bax, Bcl-2, and Cleaved caspase3) in lung tissues were detected by western blot. Autodock performs molecular docking. RESULTS Compared to the acute hypobaric hypoxia group, norwogonin administration remarkably decreased the water content and pathological changes in lung tissues, reduced the levels of H2O2, MDA, IL-1β, TNF-α, and IL-6, elevated the levels of SOD and GSH, downregulated the levels of HIF-1α, VEGF, Nrf2, HO-1, NF-κB, TNF-α, Bax and cleaved caspase-3 proteins expression, upregulated the Bcl-2 protein expression, and reduced the Bax/Bcl-2 ratio. Molecular docking results indicated that norwogonin exhibited strong binding abilities with Nrf2 and HO-1. CONCLUSION Norwogonin alleviates oxidative stress, reduces inflammatory response, and inhibits apoptosis by activating Nrf2/HO-1 signaling pathway, thereby improving acute hypobaric hypoxia induced lung tissue injury in mice.