The role of HIF prolyl hydroxylase-2 (PHD2) during physiological and pathological processes in mice

HIF脯氨酰羟化酶2（PHD2）在小鼠生理和病理过程中的作用

• 批准号: 35183441
• 负责人: Professor Dr. Ben Wielockx, Ph.D.
• 金额: --
• 依托单位: Institut für Klinische Chemie und Laboratoriumsmedizin
• 依托单位国家: 德国
• 项目类别: Independent Junior Research Groups
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2012-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/35183441?language=en
• 关键词: role; HIF; prolyl; hydroxylase; PHD2

With the current proposal I would like to apply for an additional 6th Emmy Noether year. The reasoning is that apart from several recent publications, our main research results are currently either under review in a high impact factor journal or almost ready to be submitted. Moreover, based on the research performance of my group, the department of hematology (TU Dresden) has committed itself to apply with me for a Heisenberg professorship in the future. Therefore, I believe that this 6th E.N. year would be an excellent opportunity to publish our results, finalize other promising research lines and get qualified for a professorship. During the last 4.5 years, research in our group has been focused on the role of oxygen-sensors in mice. These proteins are indispensable in all living beings as it enables the cells to instantaneously adapt to inappropriate pO2. This machinery mainly relies on the HIF-prolyl hydroxylases (PHD1-3), enzymes that hydroxylate hypoxia inducible factor (HIF) and lead to their inactivation. Using different genetic approach we found that PHD2 is of utmost importance during the control of red blood cell mass, skin wound healing and maintenance of hematopoietic stem cells (HSCs) (Franke et al., under review). Using a new conditional PHD2 deficient mouse line (CD68:cre-PHD2f/f) we showed that loss of PHD2 in the HSC compartment induces self-renewal of multipotent progenitors (MPP) and HSCs in a HIF1a-dependent manner. During this additional E.N research year we want to expand these findings. Although we found a direct link between PHD2 and HIF1a in HSCs, we propose to perform gene profiling on the most immature hematopoietic cells under severe stress. We are convinced that this will enable us to find the responsible genes involved in PHD2-related inhibition of differentiation in HSCs and maintaining of their multipotency. Our findings have also important implications with regard to hematological malignancies. We therefore plan to study the PHD2-HIF1 angle in a newly developed acute myeloid leukemia mouse model (AML) using our Vav:cre-PHD2f/f mice; deficient for PHD2 only in the hematopoietic system. In an acute colitis model we found that CD68:cre-PHD2f/f mice are much more susceptible than their WT counterparts. Intense research has now demonstrated that PHD2-deficiency in colon epithelial cells is responsible for this sensitivity although independent of their hydroxylation activity. During this extra year we want to perform some very defined ex vivo experiments that will help us to find the responsible pathway (e.g. TGFbeta, NFkB…). In a recent Cancer Research publication from our group we described in detail the role of PHD2 during tumor development. We now also found that loss of PHD2 in myeloid and T-cells can control tumor growth. Using genetically induced tumor models (MMTV-pyMT-cre-PHD2f/f) we will expand these findings in search of the role of PHD2 in inflammatory cells during tumor development in a clinically relevant model.

根据目前的提议，我想申请明年的第六届艾美奖。原因是，除了最近发表的几篇论文外，我们的主要研究成果目前要么在高影响因子期刊上审稿，要么即将提交。此外，根据我的小组的研究表现，德累斯顿大学血液学系承诺在未来向我申请海森堡教授职位。因此，我相信这第六届E.N.年会是一个很好的机会，可以发表我们的研究成果，确定其他有前途的研究方向，并获得教授资格。在过去的四年半里，我们小组的研究一直集中在老鼠体内氧传感器的作用上。这些蛋白质在所有生物中都是必不可少的，因为它使细胞能够立即适应不合适的pO2。这种机制主要依赖于HIF-脯氨酸羟化酶（PHD1-3），这种酶可以羟化缺氧诱导因子（HIF）并导致其失活。通过不同的遗传方法，我们发现PHD2在控制红细胞数量、皮肤伤口愈合和维持造血干细胞（hsc）过程中起着至关重要的作用（Franke等人，正在审查中）。利用一种新的条件PHD2缺陷小鼠系（CD68:cre-PHD2f/f），我们发现HSC室中PHD2的缺失以依赖hif1a的方式诱导多能祖细胞（MPP）和HSC的自我更新。在这个额外的E.N研究年度，我们希望扩展这些发现。虽然我们在造血干细胞中发现了PHD2和HIF1a之间的直接联系，但我们建议在严重应激下对最不成熟的造血细胞进行基因谱分析。我们相信，这将使我们能够找到参与phd2相关的造血干细胞分化抑制和维持其多能性的负责基因。我们的发现对血液恶性肿瘤也有重要意义。因此，我们计划在新开发的急性髓性白血病小鼠模型（AML）中研究PHD2-HIF1角度，使用我们的Vav: cree - phd2f /f小鼠；仅在造血系统中缺乏PHD2。在急性结肠炎模型中，我们发现CD68: cree - phd2f /f小鼠比WT小鼠更易感。大量研究表明，尽管与羟基化活性无关，但结肠上皮细胞中phd2的缺乏是导致这种敏感性的原因。在这额外的一年里，我们想进行一些非常明确的离体实验，这将有助于我们找到相关的途径（例如TGFbeta， NFkB…）。在我们小组最近发表的一篇癌症研究论文中，我们详细描述了PHD2在肿瘤发展过程中的作用。我们现在还发现髓细胞和t细胞中PHD2的缺失可以控制肿瘤的生长。利用基因诱导肿瘤模型（mmtv - pymt - cree - phd2f /f），我们将扩展这些发现，在临床相关模型中寻找PHD2在肿瘤发展过程中在炎症细胞中的作用。