Understanding granule disorders of myeloid cells by unravelling the interactome and function of the Nbeal2 protein

我们有三种血细胞：红血球为我们的组织输送氧气，白血球对抗感染，血小板防止出血。血小板是一种智能设备，可以使血液凝结在适当的位置，适量地止血，并使受损的血管壁愈合。中性粒细胞是一种白细胞，通过形成捕捉器来捕捉细菌并产生化学物质来杀死它们来对抗感染。它们良好作用的另一面是，这两种细胞可以共同作用，使血液凝块变得过于强烈。这可能会导致血栓，阻止血液到达心脏或大脑，导致心脏病发作或中风。进行研究以更好地了解这些细胞的功能是如何调节的，这一点很重要。作为一名血液学医生，我诊断和治疗患有血液病的患者，我有一个想法，基于非常罕见的遗传性出血情况，灰色血小板综合征(GPS)，我有一个想法来了解这些细胞是如何工作的。GPS患者出血是因为他们的血小板功能不好，也可能是因为他们的白细胞功能不好而患上了自身免疫性疾病。剑桥的研究人员发现，NBEAL2基因DNA密码的变化会导致GPS。我们对这种基因知之甚少，但我们确实知道，血小板和中性粒细胞缺乏某些类型的颗粒。这些颗粒就像包含许多蛋白质的包裹，细胞释放这些蛋白质来帮助完成它们的重要功能。因此，来自GPS患者的血小板和中性粒细胞未能止血或形成细菌捕捉器也就不足为奇了。为了更好地了解Nbeal2蛋白的功能，研究人员在小鼠身上禁用了Nbeal2基因。除了血液系统有问题外，这些小鼠的骨骼也很脆弱，不受癌症扩散的影响，这表明Nbeal2蛋白参与了许多重要功能。可以合理地假设Nbeal2不是单独作用的，而是与许多其他蛋白质一起工作来形成和保留颗粒。最近的研究结果表明，它与的其他蛋白质一起工作。我提出的这个项目是为了找出这群人中对颗粒功能至关重要的蛋白质。要做到这一点，我将使用两种不同但互补的方法。首先，我将研究在GPS患者中发现的Nbeal2蛋白的变化如何改变与其伙伴蛋白的相互作用。我将使用一项新技术在干细胞中引入NBEAL2基因的变化。然后，我将指示这些基因修饰的干细胞成为制造血小板的专门细胞。我将使用这些专门的细胞，并与邓迪的研究人员合作，确定基因编辑是否导致了蛋白质相互作用的变化。其次，我将与数学家合作，调查在原因不明的血小板疾病患者中，Nbeal2蛋白的基因是否发生了变化。剑桥的研究人员与英国和海外医院的医生合作，与被诊断为罕见的血小板疾病的家庭进行了接触。这些无法解释的疾病很可能是由它们的DNA密码改变引起的。为了发现这些变化，到目前为止，他们已经破译了1013名患者的整个DNA密码。如果我成功识别出一种假定的新致病基因，我将邀请受影响的家庭进行进一步的研究，以证实这一观察结果。我相信，从我的项目中获得的知识将有助于发现对血细胞中颗粒的形成和功能至关重要的新基因和蛋白质。这项研究可能会给遗传性血细胞疾病患者的护理带来立竿见影的好处，因为我们可以很容易地引入DNA测试，以便更快速地诊断。我还希望，从长远来看，我的研究发现将为心脏病发作和中风的预防和治疗带来改进。

We have three types of blood cells; red cells carry oxygen to our tissues, white cells fight infections and platelets prevent bleeding. Platelets are smart devices that make the blood clot in the right place, by the right amount, to stop bleeding and allow healing of the damaged vessel wall. Neutrophils, a type of white cell, fight infections by forming traps to capture bugs and producing chemicals to kill them. The flipside to their good roles is that both cells can work together to make blood clot too vigorously. This may lead to clots that prevent blood from reaching the heart or brain, causing a heart attack or stroke. It is important to perform research to better understand how the function of these cells is regulated. As a haematology doctor I diagnose and treat patients with blood disorders and I have an idea to gain insight into how these cells work based on the very rare inherited bleeding condition Gray Platelet Syndrome (GPS). Patients with GPS bleed because their platelets do not function well and may also have autoimmune disease because their white cells do not function well either. Researchers in Cambridge have discovered that changes in the DNA code of the gene NBEAL2 cause GPS. Not a lot is known about this gene but we do know that the platelets and neutrophils lack certain types of granules. These granules are like packages containing many proteins, which the cells release to help fulfil their important functions. It is not surprising, therefore, that platelets and neutrophils from patients with GPS fail to arrest bleeding or form traps for bugs. To better understand the function of the Nbeal2 protein researchers disabled the Nbeal2 gene in mice. As well as having problems with the blood system, these mice also have fragile bones and are protected from the spread of cancer showing that the Nbeal2 protein is involved in many important functions. It is reasonable to assume that Nbeal2 does not act alone, but works together with many other proteins to form and retain granules. Results from recent research indicates it works with 64 other proteins. The project I propose is to identify the critical proteins for granule function within this group of 64. To do this, I will use two different but complementary approaches. Firstly, I will investigate how changes in the Nbeal2 protein identified in patients with GPS alters the interaction with its 64 partner proteins. I will use a new technology to introduce changes in the NBEAL2 gene in stem cells. I will then instruct these gene-modified stem cells to become specialised cells that make platelets. I will use these specialised cells and work with researchers in Dundee to determine whether the gene editing has caused changes in the protein interactions. Secondly, I will work with mathematicians to investigate whether any of the 64 genes for the Nbeal2 partner proteins are changed in patients with unexplained platelet disorders. Researchers in Cambridge have worked with doctors in hospitals in the UK and overseas to engage with families diagnosed with rare platelet disorders. It is very likely that these unexplained disorders are caused by a change in their DNA code. To find these changes they have so far deciphered the entire DNA code of 1013 patients. If I succeed in identifying a presumed new disease-causing gene, then I will invite the affected families for further research studies to confirm this observation.My belief is that the knowledge gained from my project will facilitate the discovery of new genes and proteins which are important for the formation and function of granules in blood cells. The research may bring immediate benefits to the care of patients with inherited blood cell disorders because we can readily introduce a DNA test for more rapid diagnosis. I also hope that in the long term the discoveries made by my research will bring improvements to the prevention and treatment of heart attacks and strokes.