Sen Tanusree, Sen Nilkantha
Department of Neuroscience and Regenerative Medicine, Augusta University, United States; Department of Veterinary Biosciences & Diagnostic Imaging, College of Veterinary Medicine, The University of Georgia, United States.
Department of Neuroscience and Regenerative Medicine, Augusta University, United States.
Neuropharmacology. 2016 Aug;107:79-88. doi: 10.1016/j.neuropharm.2016.03.009. Epub 2016 Mar 9.
Traumatic brain injury (TBI) is one of the major cause of morbidity and mortality and it affects more than 1.7 million people in the USA. A couple of regenerative pathways including activation of hypoxia-inducible transcription factor 1 alpha (HIF-1α) are initiated to reduce cellular damage following TBI; however endogenous activation of these pathways is not enough to provide neuroprotection after TBI. Thus we aimed to see whether sustained activation of HIF-1α can provide neuroprotection and neurorepair following TBI. We found that chronic treatment with dimethyloxaloylglycine (DMOG) markedly increases the expression level of HIF-1α and mRNA levels of its downstream proteins such as Vascular endothelial growth factor (VEGF), Phosphoinositide-dependent kinase-1 and 4 (PDK1, PDK4) and Erythropoietin (EPO). Treatment of DMOG activates a major cell survival protein kinase Akt and reduces both cell death and lesion volume following TBI. Moreover, administration of DMOG augments cluster of differentiation 31 (CD31) staining in pericontusional cortex after TBI, which suggests that DMOG stimulates angiogenesis after TBI. Treatment with DMOG also improves both memory and motor functions after TBI. Taken together our results suggest that sustained activation of HIF-1α provides significant neuroprotection following TBI.
创伤性脑损伤(TBI)是发病和死亡的主要原因之一,在美国,它影响着超过170万人。TBI后会启动一些再生途径,包括缺氧诱导转录因子1α(HIF-1α)的激活,以减少细胞损伤;然而,这些途径的内源性激活不足以在TBI后提供神经保护。因此,我们旨在研究HIF-1α的持续激活是否能在TBI后提供神经保护和神经修复。我们发现,用二甲基乙二酰甘氨酸(DMOG)进行慢性治疗可显著提高HIF-1α的表达水平及其下游蛋白如血管内皮生长因子(VEGF)、磷酸肌醇依赖性激酶-1和4(PDK1、PDK4)以及促红细胞生成素(EPO)的mRNA水平。DMOG治疗可激活主要的细胞存活蛋白激酶Akt,并减少TBI后的细胞死亡和损伤体积。此外,给予DMOG可增强TBI后挫伤周围皮质中分化簇31(CD31)的染色,这表明DMOG可刺激TBI后的血管生成。用DMOG治疗还可改善TBI后的记忆和运动功能。综上所述,我们的结果表明,HIF-1α的持续激活在TBI后可提供显著的神经保护。