TROY通过结合RhoGDIα调控人脑微血管内皮细胞介导的血管生成的机制研究

脑血管生成为脑发育必需，并参与肿瘤等疾病。人脑微血管内皮细胞（HBMEC）通过增殖、迁移、出芽介导血管生成；胶质母细胞瘤样干细胞（GBM-SLC）还可转分化为HBMEC，促使血管生成。研究发现TROY可调控脑血管生成，但机制不清。本课题在前期发现①TROY基因敲减后，HBMEC迁移能力下降；②TROY通过结合RhoGDIα激活RhoA/ROCK通路；③TROY激活NF-κB，促进胶质母细胞瘤生长的基础上，提出“TROY通过结合RhoGDIα，调控RhoA/ROCK/IKKβ/NF-κB活性，促进生理和胶质母细胞瘤条件下的血管生成”的假设。拟在细胞和整体水平，研究TROY/RhoGDIα结合是否①受到促血管生成信号的调控；②调控RhoA/ROCK/IKKβ/NF-κB活性；③调控HBMEC的增殖、迁移和出芽；④参与GBM-SLC向HBMEC的转分化，验证该假设。

Angiogenesis (the growth of new blood vessels) is crucial for brain shaping and blood-brain barrier (BBB) development. It also plays an essential role in multiple brain diseases such as glioblastoma...Cerebral angiogenesis is typically fulfilled by human brain microvascular endothelial cell (HBMEC) through proliferation, migration as well as sprouting. Besides these cellular processes, transdifferentiation of glioblastoma stem-like cell (GBM-SLC) into HBMEC also plays an essential role in glioblastoma-induced angiogenesis. ..Recent study has identified the role of TROY protein in brain angiogenesis and BBB formation. However, the underlying mechanisms remain elusive. ..Our ongoing research demonstrated that Rho guanine nucleotide dissociation inhibitor (RhoGDIα) acted as a binding partner of TROY and mediated RhoA/ROCK activation and following neurite extension inhibition induced by Nogo-A, a member of myelin-associated inhibitory factors. Furthermore, TROY was found to be overexpressed in human glioblastoma samples. TROY knockdown suppressed glioblastoma growth through inhibition of NF-κB signaling. Most of all, when TROY expression was reduced by shRNA transfection, the migration of HBMEC stimulated by vascular endothelial growth factor (VEGF) was significantly inhibited...Based on these findings, we proposed that TROY might interact with RhoGDIα to activate RhoA/ROCK/IKKβ/NF-κB pathway, thereby promoting cerebral angiogenesis mediated by HBMEC. ..To testify this hypothesis, the following four topics will be dealt with in the study. Firstly, we want to know whether TROY/RhoGDIα interaction will be enhanced by VEGF, a potent proangiogenic factor. Secondly, the effects of TROY/RhoGDIα interaction on RhoA/ROCK/IKKβ/NF-κB activation will be tested in HBMEC. Thirdly, the key cellular processes involved in ROY/RhoGDIα interaction-induced angiogenesis and their underlying signaling mechanisms will be explored. Last but not the least, we aim to clarify the role of TROY/RhoGDIα signaling in the transdifferentiation of GBM-SLC into HBMEC.