OASIS modulates hypoxia pathway activity to regulate bone angiogenesis.
OASIS modulates hypoxia pathway activity to regulate bone angiogenesis.
复制标题
DOI：
10.1038/srep16455
复制
发表时间：
2015-11-12
影响因子：
4.6
通讯作者：
Imaizumi K
中科院分区：
文献类型：
--
作者：
Cui M;Kanemoto S;Cui X;Kaneko M;Asada R;Matsuhisa K;Tanimoto K;Yoshimoto Y;Shukunami C;Imaizumi K
OASIS/CREB 3L 1是一种内质网驻留转录因子，在成骨细胞分化中起重要作用。在这项研究中，我们确定了OASIS和缺氧信号通路之间的新串扰，该信号通路在骨发育过程中调节血管化。RT-PCR和实时PCR分析显示，OASIS缺陷（Oasis−/−）小鼠胚胎成纤维细胞中缺氧诱导因子-1 α（HIF-1α）靶基因（如血管内皮生长因子A（VEGFA））的表达水平显著降低。在免疫共沉淀实验中，OASIS的N末端片段（OASIS-N; OASIS的活化形式）通过bZIP结构域与HIF-1α结合。荧光素酶分析表明，OASIS-N通过低氧反应元件（HRE）促进报告基因的转录活性。此外，Oasis−/−成骨细胞中血管生成因子Vegfa的表达水平降低。免疫染色和跖骨血管生成检测显示Oasis−/−小鼠骨组织血管生成延迟。这些结果表明OASIS通过与HIF-1α蛋白相互作用影响HIF-1α靶基因的表达，OASIS-HIF-1α复合物可能在骨发育过程中的血管生成中发挥重要作用。
OASIS/CREB3L1, an endoplasmic reticulum (ER)-resident transcription factor, plays important roles in osteoblast differentiation. In this study, we identified new crosstalk between OASIS and the hypoxia signaling pathway, which regulates vascularization during bone development. RT-PCR and real-time PCR analyses revealed significant decreases in the expression levels of hypoxia-inducible factor-1α (HIF-1α) target genes such as vascular endothelial growth factor A (VEGFA) in OASIS-deficient (Oasis−/−) mouse embryonic fibroblasts. In coimmunoprecipitation experiments, the N-terminal fragment of OASIS (OASIS-N; activated form of OASIS) bound to HIF-1α through the bZIP domain. Luciferase assays showed that OASIS-N promoted the transcription activities of a reporter gene via a hypoxia-response element (HRE). Furthermore, the expression levels of an angiogenic factor Vegfa was decreased in Oasis−/− osteoblasts. Immunostaining and metatarsal angiogenesis assay showed retarded vascularization in bone tissue of Oasis−/− mice. These results suggest that OASIS affects the expression of HIF-1α target genes through the protein interaction with HIF-1α, and that OASIS-HIF-1α complexes may play essential roles in angiogenesis during bone development.