早期与延迟缺血后适应相结合通过上调局灶性缺血大鼠的ERK-CREB通路增强脑源性神经营养因子的产生。
Combination of early and delayed ischemic postconditioning enhances brain-derived neurotrophic factor production by upregulating the ERK-CREB pathway in rats with focal ischemia.
作者信息
Wu Hui, Yang Shao-Feng, Dai Jiong, Qiu Yong-Ming, Miao Yi-Feng, Zhang Xiao-Hua
机构信息
Department of Neurosurgery, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201112, P.R. China.
出版信息
Mol Med Rep. 2015 Nov;12(5):6427-34. doi: 10.3892/mmr.2015.4327. Epub 2015 Sep 15.
Ischemic postconditioning, including early and delayed ischemic postconditioning, has been recognized as a simple and promising strategy in the treatment of stroke. However, the effects of the combination of early and delayed ischemic postconditioning, and the mechanisms underlying these effects, remain unclear. The aim of the present study was to determine whether the combination of early and delayed ischemic postconditioning offers greater protection against stroke, and enhances the production of brain‑derived neurotrophic factor (BDNF). A combination of early and delayed ischemic postconditioning was established by repeated, transient occlusion and reperfusion of the ipsilateral common carotid artery in a rat model of middle cerebral artery occlusion. Infarct size, motor function, cerebral blood flow and brain edema were then evaluated, in order to confirm the effects of combinative ischemic postconditioning. TUNEL staining was used to analyze the rate of apoptosis of cells in the penumbral area. BDNF, extracellular signal‑regulated kinases 1/2 (ERK1/2) and cAMP response element‑binding protein (CREB) expression was detected using immunofluorescence staining and western blot analysis. The results of the present study indicated that the combination of early and delayed ischemic postconditioning further reduced the infarct volume, stabilized cerebral blood disturbance and attenuated neuronal apoptosis, compared with either alone. However, combinative postconditioning exerted the same effect on neurological function and brain edema, compared with early or delayed ischemic postconditioning alone. Further investigation indicated that combinative ischemic postconditioning increased the expression of BDNF, and a significantly higher number of BDNF‑positive cells was observed in neurons and astrocytes from the combined group than in the early or delayed groups. Combinative ischemic postconditioning also induced the phosphorylation of ERK1/2 and CREB in the cortex, following focal ischemia. The results of the present study suggest that the combination of early and delayed ischemic postconditioning may further reduce brain ischemic reperfusion injury following focal ischemia, compared with either treatment alone. In addition, it induces the production of BDNF in neurons and astrocytes. Furthermore, the effects of combinative ischemic postconditioning may be mediated by the activation of ERK1/2 and CREB.
缺血后适应,包括早期和延迟缺血后适应,已被公认为是一种治疗中风的简单且有前景的策略。然而,早期和延迟缺血后适应联合应用的效果以及这些效果背后的机制仍不清楚。本研究的目的是确定早期和延迟缺血后适应联合应用是否能为中风提供更大的保护,并增强脑源性神经营养因子(BDNF)的产生。通过在大脑中动脉闭塞大鼠模型中反复短暂阻断和再通同侧颈总动脉,建立早期和延迟缺血后适应联合应用的模型。然后评估梗死体积、运动功能、脑血流量和脑水肿,以确认联合缺血后适应的效果。采用TUNEL染色分析半暗带区细胞凋亡率。使用免疫荧光染色和蛋白质印迹分析检测BDNF、细胞外信号调节激酶1/2(ERK1/2)和cAMP反应元件结合蛋白(CREB)的表达。本研究结果表明,与单独应用早期或延迟缺血后适应相比,早期和延迟缺血后适应联合应用进一步减小了梗死体积,稳定了脑血流紊乱并减轻了神经元凋亡。然而,与单独应用早期或延迟缺血后适应相比,联合后适应对神经功能和脑水肿的影响相同。进一步研究表明,联合缺血后适应增加了BDNF的表达,联合组神经元和星形胶质细胞中BDNF阳性细胞的数量明显高于早期或延迟组。联合缺血后适应还在局灶性缺血后诱导了皮质中ERK1/2和CREB的磷酸化。本研究结果表明,与单独应用任一治疗方法相比,早期和延迟缺血后适应联合应用可能进一步减轻局灶性缺血后的脑缺血再灌注损伤。此外,它诱导神经元和星形胶质细胞产生BDNF。此外,联合缺血后适应的作用可能是通过ERK1/2和CREB的激活介导的。