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

根据目前的提议，我想再申请第六届艾美奖。理由是，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正在一家高影响力期刊上进行审查，要么几乎准备提交。此外，基于我的团队的研究表现，德累斯顿州立大学血液学系已承诺未来将与我一起申请海森伯格教授一职。因此，我相信今年第六个E.N.年将是一个极好的机会来发表我们的结果，敲定其他有希望的研究路线，并获得教授职位的资格。在过去的4.5年里，我们小组的研究一直集中在氧气传感器在小鼠身上的作用上。这些蛋白质对所有生物来说都是不可或缺的，因为它使细胞能够瞬间适应不适当的pO2。这一机制主要依赖于缺氧诱导因子(HIF)羟化酶(Phd1-3)，该酶可使缺氧诱导因子(HIF)羟化并导致其失活。使用不同的遗传方法，我们发现PHD2在控制红细胞质量、皮肤伤口愈合和维持造血干细胞(HSCs)方面起着至关重要的作用(Franke等人，正在审查中)。利用一种新的条件性PHD2缺陷小鼠品系(CD68：Cre-PHD2f/f)，我们发现HSC中PHD2的缺失可以诱导多能祖细胞(MPP)和HSCs以HIF1a依赖的方式自我更新。在这个额外的E.N研究年度，我们希望扩大这些发现。虽然我们在HSCs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图谱分析。我们相信，这将使我们能够找到与PHD2相关的抑制HSCs分化和维持其多能性相关的负责基因。我们的发现对血液系统恶性肿瘤也有重要意义。因此，我们计划使用我们的Vav：Cre-PHD2f/f小鼠来研究新开发的急性髓系白血病小鼠模型(AML)中的PHD2-HIF1角度；仅在造血系统中缺乏PHD2。在急性结肠炎模型中，我们发现CD68：Cre-PHD2f/f小鼠比WT小鼠更容易感染。密集的研究已经证明，结肠上皮细胞中PHD2缺乏是造成这种敏感性的原因，尽管与其羟化活性无关。在这额外的一年里，我们希望进行一些非常明确的体外实验，以帮助我们找到负责的途径(例如，TGFbeta，NFkB…)。在我们团队最近发表的一篇癌症研究出版物中，我们详细描述了PHD2在肿瘤发生中的作用。我们现在还发现，髓系细胞和T细胞中PHD2的缺失可以控制肿瘤的生长。利用基因诱导的肿瘤模型(MMTV-PYMT-CRE-PHD2f/f)，我们将扩展这些发现，以寻找在临床相关模型中PHD2在肿瘤发展过程中炎性细胞中的作用。

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.