Josipovic I, Fork C, Preussner J, Prior K-K, Iloska D, Vasconez A E, Labocha S, Angioni C, Thomas D, Ferreirós N, Looso M, Pullamsetti S S, Geisslinger G, Steinhilber D, Brandes R P, Leisegang M S
Institute for Cardiovascular Physiology, Goethe-University, Frankfurt, Germany.
German Center for Cardiovascular Research (DZHK), Partner site RheinMain, Frankfurt, Germany.
Acta Physiol (Oxf). 2016 Sep;218(1):13-27. doi: 10.1111/apha.12700. Epub 2016 May 20.
Platelet-activating factor acetyl hydrolase 1B1 (PAFAH1B1, also known as Lis1) is a protein essentially involved in neurogenesis and mostly studied in the nervous system. As we observed a significant expression of PAFAH1B1 in the vascular system, we hypothesized that PAFAH1B1 is important during angiogenesis of endothelial cells as well as in human vascular diseases.
The functional relevance of the protein in endothelial cell angiogenic function, its downstream targets and the influence of NONHSAT073641, a long non-coding RNA (lncRNA) with 92% similarity to PAFAH1B1, were studied by knockdown and overexpression in human umbilical vein endothelial cells (HUVEC).
Knockdown of PAFAH1B1 led to impaired tube formation of HUVEC and decreased sprouting in the spheroid assay. Accordingly, the overexpression of PAFAH1B1 increased tube number, sprout length and sprout number. LncRNA NONHSAT073641 behaved similarly. Microarray analysis after PAFAH1B1 knockdown and its overexpression indicated that the protein maintains Matrix Gla Protein (MGP) expression. Chromatin immunoprecipitation experiments revealed that PAFAH1B1 is required for active histone marks and proper binding of RNA Polymerase II to the transcriptional start site of MGP. MGP itself was required for endothelial angiogenic capacity and knockdown of both, PAFAH1B1 and MGP, reduced migration. In vascular samples of patients with chronic thromboembolic pulmonary hypertension (CTEPH), PAFAH1B1 and MGP were upregulated. The function of PAFAH1B1 required the presence of the intact protein as overexpression of NONHSAT073641, which was highly upregulated during CTEPH, did not affect PAFAH1B1 target genes.
PAFAH1B1 and NONHSAT073641 are important for endothelial angiogenic function.
血小板活化因子乙酰水解酶1B1（PAFAH1B1，也称为Lis1）是一种主要参与神经发生且大多在神经系统中研究的蛋白质。由于我们观察到PAFAH1B1在血管系统中有显著表达，我们推测PAFAH1B1在内皮细胞血管生成以及人类血管疾病过程中很重要。
通过在人脐静脉内皮细胞（HUVEC）中进行敲低和过表达，研究该蛋白在内皮细胞血管生成功能中的功能相关性、其下游靶点以及与PAFAH1B1有92%相似性的长链非编码RNA（lncRNA）NONHSAT073641的影响。
敲低PAFAH1B1导致HUVEC管形成受损以及在球体试验中芽生减少。相应地，PAFAH1B1的过表达增加了管数量、芽长度和芽数量。lncRNA NONHSAT073641表现相似。PAFAH1B1敲低及其过表达后的微阵列分析表明该蛋白维持基质Gla蛋白（MGP）的表达。染色质免疫沉淀实验表明，活性组蛋白标记以及RNA聚合酶II与MGP转录起始位点的正确结合需要PAFAH1B1。MGP自身是内皮血管生成能力所必需的，同时敲低PAFAH1B1和MGP会降低迁移能力。在慢性血栓栓塞性肺动脉高压（CTEPH）患者的血管样本中，PAFAH1B1和MGP上调。PAFAH1B1的功能需要完整蛋白的存在，因为在CTEPH期间高度上调的NONHSAT073641的过表达不影响PAFAH1B1靶基因。
PAFAH1B1和NONHSAT073641对内皮血管生成功能很重要。
