Xiaowei H, Ninghui Z, Wei X, Yiping T, Linfeng X
Laboratory for Conservation and Utilization of Bio-resources, Yunnan University, Kunming, PR China.
Spinal Cord. 2006 Jan;44(1):35-43. doi: 10.1038/sj.sc.3101813.
Animal model of compressive spinal cord injury (SCI), reverse transcription-polymerase chain reaction (RT-PCR), in situ hybridization (ISH), immunohistochemistry (IHC) and enzymehistochemistry (EHC) were used to test the hypothesis that hypoxia-inducible factor-1alpha (HIF-1alpha) and the target genes activated by HIF-1alpha are involved in cell hypoxia tolerance and tissue vascularity to help injured tissue to go through the stress disease.
To determine whether HIF-1alpha and its target genes associated with hypoxia tolerance and neovascularization take part in the pathophysiological procedure of SCI in rats.
Yunnan University, China.
Random-bred adult male Sprague-Dawley (SD) rats weighing 250+/-50 g were prepared for compressive SCI models. After receiving compressive injury at T(10), rats were sacrificed at different times from 6 h to 1 week after injury. The injured cords were removed, and HIF-1alpha and its target genes were assayed by RT-PCR, ISH, IHC and EHC. The data were statistically analyzed.
An increase in HIF-1alpha mRNA expression was observed 12 h postinjury, reached a maximum at 3 days, and reduced gradually thereafter. HIF-1alpha protein expressed earlier than HIF-1alpha mRNA. Additionally, two glycolytic enzymes and vascular endothelial growth factor (VEGF), which are regulated by HIF-1alpha, also increased after an interval postinjury, and their expression patterns shared a same trend with that of HIF-1alpha protein.
The findings suggested that the most important hypoxic regulatory factor HIF-1alpha was upregulated in involved cells by activating the transcription and increasing protein stability, and subsequently activated the expression of HIF-1alpha target genes, including glycolytic enzymes and VEGF in SCI. Combined with the pathologic observation, it suggested that overexpression of HIF-1alpha and its target genes might take part in hypoxia tolerance and vascularity of the injured spinal cord.
采用脊髓压迫性损伤（SCI）动物模型、逆转录-聚合酶链反应（RT-PCR）、原位杂交（ISH）、免疫组织化学（IHC）和酶组织化学（EHC）来验证以下假说：缺氧诱导因子-1α（HIF-1α）及其激活的靶基因参与细胞缺氧耐受性和组织血管生成，以帮助损伤组织度过应激疾病。
确定与缺氧耐受性和新生血管形成相关的HIF-1α及其靶基因是否参与大鼠SCI的病理生理过程。
中国云南大学。
选用体重250±50 g的成年雄性随机繁殖Sprague-Dawley（SD）大鼠制备脊髓压迫性损伤模型。在T10水平受到压迫性损伤后，于损伤后6小时至1周的不同时间点处死大鼠。取出损伤的脊髓，通过RT-PCR、ISH、IHC和EHC检测HIF-1α及其靶基因。对数据进行统计学分析。
损伤后12小时观察到HIF-1α mRNA表达增加，在3天时达到最大值，此后逐渐降低。HIF-1α蛋白表达早于HIF-1α mRNA。此外，受HIF-1α调控的两种糖酵解酶和血管内皮生长因子（VEGF）在损伤后的一段时间后也增加，其表达模式与HIF-1α蛋白相同。
研究结果表明，最重要的缺氧调节因子HIF-1α通过激活转录和增加蛋白质稳定性在受累细胞中上调，随后激活HIF-1α靶基因的表达，包括SCI中的糖酵解酶和VEGF。结合病理观察结果，提示HIF-1α及其靶基因的过表达可能参与损伤脊髓的缺氧耐受性和血管生成。
