利用幹細胞建立周邊神經退化模式

Abstract

周邊神經退化性疾病會對我們身體的活動帶來許多影響，像是說話、行走、呼吸，或是臟器功能。大多數的周邊神經退化性疾病是嚴重且致命的，雖然並沒有列於全球十大死因，但根據流病學統計，在西元2040年以前，神經退化性疾病很有可能會超越癌症。有鑑於此，在近幾十年來，越來越多的研究團隊投入於周邊神經退化性疾病的研究當中。到目前為止，大多數對於周邊神經退化性疾病的研究，還是利用動物模式，或是大鼠背根神經節細胞株，但這些研究結果將會面臨無法完整詮釋人體內情形的困境，與此同時，人類的背根神經節細胞也同樣面臨取得不易的問題，所以要如何建立一個利用人類細胞來進行研究的周邊神經退化模式會是我們的當務之急。誘導性多潛能幹細胞在近幾年是個非常熱門的研究題材，在疾病模式、藥物篩選，以及細胞療法上都逐漸展露頭角，除了具有多潛能分化能力以及自我更新能力，誘導性多潛能幹細胞也解決了以往利用胚胎幹細胞所造成的道德倫理問題，在疾病治療方面減少了免疫排斥反應，而在研究上，利用病人的誘導性多潛能幹細胞則可模擬疾病的基因背景。所以在本篇實驗中，我們將會利用誘導性多潛能幹細胞來建立一個周邊神經退化模式。我們將三株來自健康人的誘導性多潛能幹細胞，用先前發表的分化方法，將幹細胞分化成周邊感覺神經細胞，並將兩種已知會造成神經受損的藥物: 辣椒素及長春新鹼，加入培養液中，來看在我們建立的模式中，這兩種藥物是否也能對神經纖維及細胞本體造成影響。

Peripheral nerve degeneration diseases affect many body activities, such as breathing, talking, moving, and organ functions. Most of these diseases can be serious and life-threatening. Although they do not rank among the top ten causes of death in the world, they will outpace the cancers up to 2040 A.D. according to epidemiological statistics. That is why the studies on this topic become more and more popular in recent decades. So far, most of the studies about nerve degeneration use animal models. Meanwhile, it is difficult to get human dorsal root ganglian (DRG) neurons to do primary culture. Therefore, the top priority is to set up a human cell model that can facilitate the study of nerve degeneration in cellular context. Induced pluripotent stem cells (iPSCs) become a flourishing research tool in recent years, not only due to their abilities of multi-differentiation potential and self-renewal, but also, reducing some obstacles, such as ethical constrains, in using human samples. Furthermore, the applications of iPSCs are extensive, in addition to disease modeling, they also provide an avenue to drug screening and cell therapy. In this study, we aimed to set up a stem cell model of nerve degeneration based on iPSCs. We use the iPSC cell lines from three healthy individuals, and differentiate them into peripheral sensory nerve according to published protocols. Two kinds of drug: capsaicin and vincristine, which have been known to cause neuron injury, were added into the differentiation medium, to see whether they can affect the neurite length and neuron numbers in this model.