LINEAGE CONVERSION OF BLOOD-DERIVED ENDOTHELIAL PROGENITOR CELLS TO AN ADRENOCORTICAL PHENOYPE: A NEW TECHNOLOGY TO STUDY THE ADRENAL GLAND.

肾上腺是内分泌系统的一部分，它向血液系统释放激素。每个肾上腺在解剖学上和功能上都由两个不同的部分组成，即外皮层和内髓质。肾上腺皮质对生命至关重要：它产生调节身体新陈代谢的糖皮质激素和影响血压的矿物皮质激素。肾上腺皮质紊乱会导致肾上腺分泌过多或不足的激素；有些疾病可以通过基因突变来确定。肾上腺研究通常通过使用从肿瘤或转染了感兴趣基因的细胞系建立的细胞系来进行：这两种系统都有一些缺点，例如无法产生完整的类固醇谱，或者从过表达系统推断生理相关数据的固有困难。动物模型也经常被用来研究肾上腺的发育、功能和病理，以及测试新的治疗方法和毒理学研究。然而，通过敲除技术获得的一些动物模型不能产生人类疾病（肾上腺领域的aaa综合征和NNT依赖性家族性糖皮质激素缺乏症是两个例子）。细胞重编程技术正在成为取代动物模型和程序以及研究特定疾病的原因和药物测试的强大工具。细胞重编程描述了一个完全分化的、特化的细胞类型被诱导转化为另一种在正常生理条件下不会变成的细胞类型的过程。细胞重编程已经通过多种方法实现，包括体细胞核转移，细胞-细胞融合，以及最近通过引入转录因子。2012年，英国的约翰·戈登爵士（Sir John Gordon）和日本的山中伸弥（Shinya Yamanaka）两位科学家因在该领域的突破性发现而获得诺贝尔生理学和医学奖。戈登在1962年进行的研究表明，逆转细胞的特化是可能的。通过将青蛙肠细胞的细胞核移植到青蛙去核的卵细胞中，他得到了一只蝌蚪。在Gordon工作的基础上，Yamanaka在2006年发表了一篇论文，证明通过表达编码四种转录因子的基因，成熟的小鼠细胞可以变成未成熟的干细胞（称为诱导多能干细胞，IPSCs）。IPSCs可以通过特定的方法分化为多种组织。山中伸弥的突破为研究疾病、开发诊断和治疗方法打开了大门。最近，通过使用特定的细胞命运转录因子，在不需要IPSCs中间体的情况下，从一种不相关的细胞类型生成一种细胞类型。这个过程被称为沿袭转换。无论使用何种方法，皮肤成纤维细胞迄今为止一直是主要的材料来源，但需要侵入性外科手术（皮肤活检）来建立原代细胞，但并不总是可能的。抽血将是获得供体特异性细胞的理想起点，因为它是微创的，并且已经建立了获取和处理的程序。事实上，科学家们最近已经采用这种对病人友好的方法建立了血液来源细胞的长期体外培养，重要的是，他们已经能够有效地将这些细胞重新编程为IPSCs。其中一种细胞类型是晚期生长内皮祖细胞（L-EPCs）。有了这个建议，我的目标是开发一种技术，使L-EPCs重新编程，以获得肾上腺皮质表型，使用谱系转换，通过强迫表达单细胞命运调节剂，甾体生成因子1。

The adrenal glands are part of the endocrine system, which releases hormones into the blood system. Each adrenal gland is anatomically and functionally composed of two distinct parts, an outer cortex and inner medulla. The adrenal cortex is essential for life: it produces glucocorticoids that regulate body metabolism, and mineralocorticoids that affect blood pressure. Adrenal cortex disorders can cause your adrenal glands to produce too much or not enough hormones; some disorders can be determined by genetic mutations. Adrenal studies are usually carried out by using cell lines established from tumors or cell lines transfected with a gene of interest: both systems have several drawbacks such as the inability to produce a full steroid profile or the inherent difficulty to extrapolate physiologically relevant data from an over-expression system. Animal models are also frequently used to investigate the development, function and pathology of adrenal glands, as well as for testing new treatments and for toxicology studies. However some animal models obtained through knockout technology fail to generate the human disease (Triple-A syndrome and NNT dependent-Familial Glucocorticoid Deficiency are two examples in the adrenal field). Cell reprogramming techniques are becoming powerful tools for replacing animal models and procedures as well as for studying the cause of a particular disease and for drug testing. Cellular reprogramming describes the process where a fully differentiated, specialized cell type is induced to transform into a different cell type that it would not otherwise become under normal physiological conditions. Cellular reprogramming has been achieved using a variety of methods, including somatic cell nuclear transfer, cell-cell fusion and, most recently, through the introduction of transcription factors. Two scientists, Sir John Gordon of Britain and Shinya Yamanaka of Japan were awarded the Nobel Prize for the category Physiology and Medicine in 2012 for their groundbreaking discoveries in the field. Gordon's research was conducted in 1962 and showed that it was possible to reverse the specialization of cells. By transferring a nucleus from a frog's intestinal cell into a frog's egg cell that had its nucleus removed, he was able to obtain a tadpole. Building on Gordon's work, Yamanaka published a paper in 2006 demonstrating that mature murine cells can become immature stem cells (called inducible pluripotent stem cells, IPSCs) by expressing genes encoding four transcription factors. IPSCs can be differentiated to several tissues using specific protocols. Yamanaka's breakthrough opened the door to studying disease and developing diagnosis and treatments. Recently, the generation of a cell type from an unrelated cell type without the need of an IPSCs intermediate has been described by using specific cell fate-transcription factors. This process has been named lineage conversion. Regardless of the method used, skin fibroblasts have been a predominant source material so far but an invasive surgical procedure (skin biopsy) is required to establish primary cells, and not always possible. A blood draw would be an ideal starting point to obtain donor-specific cells because it is minimally invasive and established procedures are already in place for acquisition and handling. In fact, scientists have recently employed this patient-friendly way to establish long-term in vitro culture of blood-derived cells, and importantly, they have been able to reprogram efficiently these cells into IPSCs. One of these cell types are late-outgrowth endothelial progenitor cells (L-EPCs).With this proposal, I aim at developing a technology whereby L-EPCs are reprogrammed to acquire an adrenocortical phenotype using lineage conversion, by forcing the expression of single cell fate regulator, Steroidogenic Factor 1.