School of Medicine, Quzhou College of Technology, Quzhou, Zhejiang, China.
Department of Urology, The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, Zhejiang, China.
Brain Behav. 2024 Sep;14(9):e70039. doi: 10.1002/brb3.70039.
Hypoxia inducible factor-1α (HIF-1α) is a sensitive indicator of oxygen homeostasis, of which the expression elevates following hypoxia/ischemia. This study reveals the specific mechanisms underlying the effects of HIF-1α on ischemic stroke (IS).
IS model was established using middle cerebral artery occlusion (MCAO)-modeled male rats and oxygen glucose deprivation/reoxygenation (OGD/R)-treated mice hippocampal cells HT22, followed by the silencing of HIF-1α and the overexpression of C-X-C motif chemokine receptor 4 (CXCR4) and nuclear factor-kappa B (NF-κB). Following the surgery, Garcia's grading scale was applied for neurological evaluation. Cerebral infarcts and injuries were visualized using 2,3,5-triphenyltetrazolium chloride and hematoxylin-eosin staining. The levels of tumor necrosis factor-α, Interleukin (IL)-6, IL-1β, malondialdehyde, and 8-hydroxy-2'-deoxyguanosine, were calculated via ELISA. MTT assay and lactate dehydrogenase (LDH) assay kit were adopted to determine the viability and cytotoxicity of OGD/R-modeled cells. Reactive oxygen species (ROS) generation was evaluated using a 2'-7'dichlorofluorescin diacetate (DCFH-DA) probe. The levels of HIF-1α, CXCR4, and NF-κB p65 were quantified via Western blot and immunofluorescence, respectively.
HIF-1α knockdown improved Garcia's score, attenuated the cerebral infarct, inflammation, and ROS generation, and alleviated the levels of inflammatory cytokines and CXCR4/NF-κB p65 in MCAO-modeled rats. Such effects were reversed following the overexpression of CXCR4 and NF-κB. Also, in OGD/R-treated HT22 cells, HIF-1α silencing diminished the cytotoxicity and ROS production and reduced the expressions of CXCR4/NF-κB p65, while promoting viability. However, CXCR4/NF-κB p65 overexpression did the opposite.
HIF-1α knockdown alleviates inflammation and oxidative stress in IS through the CXCR4/NF-κB pathway.
缺氧诱导因子-1α（HIF-1α）是氧平衡的敏感指标，其在缺氧/缺血后表达升高。本研究揭示了 HIF-1α 对缺血性中风（IS）影响的具体机制。
采用大脑中动脉闭塞（MCAO）模型雄性大鼠和氧葡萄糖剥夺/复氧（OGD/R）处理的小鼠海马细胞 HT22 建立 IS 模型，然后沉默 HIF-1α，过表达 C-X-C 基序趋化因子受体 4（CXCR4）和核因子-κB（NF-κB）。手术后，采用加西亚分级量表进行神经学评估。采用 2,3,5-三苯基四氮唑氯化物和苏木精-伊红染色观察脑梗死和损伤。通过 ELISA 测定肿瘤坏死因子-α、白细胞介素（IL）-6、IL-1β、丙二醛和 8-羟基-2'-脱氧鸟苷的水平。采用 MTT 法和乳酸脱氢酶（LDH）试剂盒测定 OGD/R 模型细胞的活力和细胞毒性。使用 2'-7'-二氯荧光素二乙酸酯（DCFH-DA）探针评估活性氧（ROS）的产生。通过 Western blot 和免疫荧光分别定量 HIF-1α、CXCR4 和 NF-κB p65 的水平。
HIF-1α 敲低可改善加西亚评分，减轻 MCAO 模型大鼠的脑梗死、炎症和 ROS 生成，并降低炎症细胞因子和 CXCR4/NF-κB p65 的水平。过表达 CXCR4 和 NF-κB 后，这种作用被逆转。此外，在 OGD/R 处理的 HT22 细胞中，HIF-1α 沉默减少了细胞毒性和 ROS 产生，降低了 CXCR4/NF-κB p65 的表达，同时促进了细胞活力。然而，CXCR4/NF-κB p65 的过表达则相反。
HIF-1α 敲低通过 CXCR4/NF-κB 通路减轻 IS 中的炎症和氧化应激。
