Department of Physical Therapy and Assistive Technology, National Yang Ming Chiao Tung University, Taipei 112, Taiwan.
Department of Physical Therapy, Asia University, Taichung 413, Taiwan.
Int J Mol Sci. 2022 Feb 4;23(3):1780. doi: 10.3390/ijms23031780.
Neurogenesis is a physiological response after cerebral ischemic injury to possibly repair the damaged neural network. Therefore, promoting neurogenesis is very important for functional recovery after cerebral ischemic injury. Our previous research indicated that hyperbaric oxygen therapy (HBOT) exerted neuroprotective effects, such as reducing cerebral infarction volume. The purposes of this study were to further explore the effects of HBOT on the neurogenesis and the expressions of cell migration factors, including the stromal cell-derived factor 1 (SDF1) and its target receptor, the CXC chemokine receptor 4 (CXCR4). Thirty-two Sprague-Dawley rats were divided into the control or HBO group after receiving transient middle cerebral artery occlusion (MCAO). HBOT began to intervene 24 h after MCAO under the pressure of 3 atmospheres for one hour per day for 21 days. Rats in the control group were placed in the same acrylic box without HBOT during the experiment. After the final intervention, half of the rats in each group were cardio-perfused with ice-cold saline followed by 4% paraformaldehyde under anesthesia. The brains were removed, dehydrated and cut into serial 20μm coronal sections for immunofluorescence staining to detect the markers of newborn cell (BrdU), mature neuron cell (NeuN), SDF1, and CXCR4. The affected motor cortex of the other half rats in each group was separated under anesthesia and used to detect the expressions of brain-derived neurotrophic factor (BDNF), SDF1, and CXCR4. Motor function was tested by a ladder-climbing test before and after the experiment. HBOT significantly enhanced neurogenesis in the penumbra area and promoted the expressions of SDF1 and CXCR4. The numbers of BrdU/SDF1, BrdU/CXCR4, and BrdU/NeuN cells and BDNF concentrations in the penumbra were all significantly increased in the HBO group when compared with the control group. The motor functions were improved in both groups, but there was a significant difference between groups in the post-test. Our results indicated that HBOT for 21 days enhanced neurogenesis and promoted cell migration toward the penumbra area in transient brain ischemic rats. HBOT also increased BDNF expression, which might further promote the reconstructions of the impaired neural networks and restore motor function.
神经发生是脑缺血损伤后的一种生理反应,可能有助于修复受损的神经网络。因此,促进神经发生对于脑缺血损伤后的功能恢复非常重要。我们之前的研究表明,高压氧治疗(HBOT)具有神经保护作用,例如减少脑梗死体积。本研究的目的是进一步探讨 HBOT 对神经发生的影响,以及细胞迁移因子的表达,包括基质细胞衍生因子 1(SDF1)及其靶受体 CXC 趋化因子受体 4(CXCR4)。32 只 Sprague-Dawley 大鼠接受短暂性大脑中动脉闭塞(MCAO)后分为对照组或 HBO 组。MCAO 后 24 小时开始在 3 个大气压下进行 1 小时/天的 HBOT,共 21 天。对照组大鼠在实验期间放置在相同的丙烯酸盒中,不进行 HBOT。最后一次干预后,每组大鼠的一半在麻醉下用冰冷生理盐水进行心内灌注,然后用 4%多聚甲醛灌注。取出大脑,脱水并切成 20μm 冠状连续切片,进行免疫荧光染色,以检测新生细胞(BrdU)、成熟神经元细胞(NeuN)、SDF1 和 CXCR4 的标志物。每组大鼠的另一半受影响的运动皮层在麻醉下分离,用于检测脑源性神经营养因子(BDNF)、SDF1 和 CXCR4 的表达。实验前后通过爬梯试验测试运动功能。HBOT 显著增强了半影区的神经发生,并促进了 SDF1 和 CXCR4 的表达。与对照组相比,HBOT 组半影区 BrdU/SDF1、BrdU/CXCR4 和 BrdU/NeuN 细胞数量以及 BDNF 浓度均显著增加。两组运动功能均有所改善,但组间在测试后存在显著差异。我们的结果表明,21 天的 HBOT 增强了短暂性脑缺血大鼠的神经发生,并促进了细胞向半影区迁移。HBOT 还增加了 BDNF 的表达,这可能进一步促进受损神经网络的重建并恢复运动功能。