MOLECULAR CHARACTERIZATION OF NON-MYELINATING SCHWANN CELLS

描述(申请人提供)：获得性周围神经病通常是由糖尿病、化疗和艾滋病毒/艾滋病引起的，因此给社会带来了相当大的且不断增加的卫生保健负担。神经病的有效治疗需要了解周围神经中胶质细胞和轴突之间的相互作用。髓鞘雪旺细胞已被广泛研究，但对非髓鞘雪旺细胞知之甚少。由于它们与传递疼痛的无髓鞘感觉纤维有关，它们很可能参与与糖尿病和其他小纤维神经病相关的病理。此外，雪旺细胞特有的对细胞代谢至关重要的基因突变强烈影响无髓鞘轴突的稳定性，揭示了这些细胞与周围神经疾病之间的重要但鲜为人知的联系。因此，了解非髓鞘雪旺细胞的生物学特性是开发新的周围神经疾病治疗方法的重要途径。我们已经开发了几种独立的方法来获得非髓鞘雪旺细胞的基因表达谱，以确定这些细胞的新标记，并确定它们在疾病中的功能损害，特别是代谢性疾病，影响周围神经功能的机制。此外，我们还产生了在非髓鞘雪旺细胞中表达两种蛋白的转基因小鼠，一种是EGFP标记的核糖体蛋白，另一种是他莫昔芬诱导的Cre重组酶。标记的核糖体蛋白将允许通过翻译核糖体亲和纯化(TRAP)在非髓鞘雪旺细胞中分离和分析多聚核糖体相关的mRNAs，TRAP是一种确定特定细胞类型的基因表达谱的有效方法。Cre重组酶将允许我们特异性地操纵非髓鞘雪旺细胞中的基因表达，或者完全去除它们。这样的实验对于剖析非髓鞘雪旺细胞及其相关轴突之间的复杂相互作用是必要的。这些新的转基因小鼠品系将使我们能够在遗传或环境扰动后，以及在遗传性或获得性PNS疾病模型中建立非髓鞘雪旺细胞的基因表达特征。特别是，我们将使用这些方法来研究代谢缺陷如何导致无髓鞘轴突丢失和神经病变的分子方面。通过对健康和疾病中非髓鞘雪旺细胞基因改变的鉴定和操作，我们希望对其潜在的病理机制有新的认识，并为周围神经疾病的治疗开辟新的途径。

DESCRIPTION (provided by applicant): Acquired peripheral neuropathy commonly results from diabetes, chemotherapy and HIV/AIDS, and therefore imposes a considerable, and increasing, health care burden on society. Effective treatment of neuropathy requires an understanding of the interactions between glia and axons in the peripheral nerve. Myelinating Schwann cells have been studied extensively, but less is known about non-myelinating Schwann cells. Because they are associated with unmyelinated sensory fibers that transmit pain, they are likely to participate in the pathology associated with diabetic and other small-fibe neuropathies. Furthermore, Schwann cell-specific mutations in genes that are important for cellular metabolism strongly affect unmyelinated axon stability, revealing an important but little explored link between these cells and peripheral nerve disease. Therefore an understanding of the biology of non-myelinating Schwann cells is an important approach toward developing new treatments for peripheral nerve diseases. We have developed several independent approaches for obtaining gene expression profiles of non-myelinating Schwann cells in order to identify new markers for these cells, and to identify mechanisms whereby their functional impairment in disease, particularly metabolic disease, affects peripheral nerve function. In addition, we have generated transgenic mice that express two proteins, an eGFP-tagged ribosomal protein, and tamoxifen-inducible Cre recombinase, in non-myelinating Schwann cells. The tagged ribosomal protein will permit the isolation and profiling of polyribosome-associated mRNAs in non-myelinating Schwann cells by translating ribosome affinity purification, or TRAP, a powerful method for determining gene expression profiles of specific cell types. The Cre recombinase will permit us to specifically manipulate gene expression in non-myelinating Schwann cells, or ablate them entirely. Such experiments are necessary to dissect the complex interactions between non-myelinating Schwann cells and their associated axons. These new transgenic mouse lines will permit us to establish gene expression signatures of non-myelinating Schwann cells after genetic or environmental perturbation and in models of inherited or acquired PNS disease. In particular we will use these methods to investigate the molecular aspects of how metabolic deficits lead to unmyelinated axon loss and neuropathy. Through the identification and manipulation of genes altered in non-myelinating Schwann cells in health and disease, we hope to gain new insights into the underlying pathology and open up new avenues for treatment of peripheral neuropathies.