人類乳牙牙髓幹細胞和牙根尖幹細胞神經分化之比較

Abstract

實驗目的: 人類乳牙牙髓幹細胞(stem cells from human exfoliated deciduous teeth，SHED)和人類牙根尖幹細胞(stem cells from apical papilla，SCAP)是屬於多效性的幹細胞(Multipotent stem cell)，兩種細胞經過誘導都有分化成神經細胞的能力。我們的假設是乳牙牙髓幹細胞與人類牙根尖幹細胞具有相同的神經分化能力。本實驗的目的是希望經過誘導神經分化(Neurodifferentiation)作用後比較兩種細胞神經分化的能力。 實驗方法：將兩種細胞培養誘導神經分化培養液(Neural induction medium)中一天、三天、七天、十四天、二十一天，以MTT計算活細胞的量，培養零天、一天、三天、七天、十四天、二十一天用光學顯微鏡直接觀察細胞外型變化以及反轉錄聚合酶反應（RT-PCR）和免疫螢光染色(Immuoflurorescence)來比較兩者神經分化的能力。 實驗結果：在光學顯微鏡觀察下兩種細胞在三天後就會有部分細胞變成類似神經細胞外型的改變，而在MTT的實驗中可以發現細胞在接受神經分化之培養液作用後具有細胞增生力會降低，利用反轉錄聚合酶反應和免疫螢光染色實驗發現兩種細胞具有分化成神經細胞的能力。而經過誘導後的人類牙根尖幹細胞神經纖維(Neurofilament)基因之表現上比經過誘導後乳牙牙髓幹細胞高,顯示人類牙根尖幹細胞具有較好的神經分化能力。 結論：無論是人類乳牙牙髓幹細胞或是人類牙根尖幹細胞皆具有分化成神經細胞的能力，但是人類牙根尖幹細胞比人類乳牙牙髓幹細胞具有更好神經分化的能力。我們可以預期利人類牙根尖幹細胞進行神經再生可以得到較佳的結果。

Aim：Both Stem cells from human exfoliated deciduous teeth (SHED) and Stem cells from apical papilla (SCAP) are multipotent stem cells. After neural induction, these two kinds of cells could be differentiated into neuron like cells. We hypothesized that SHED and SCAP have the same neurodifferentiation potentials. The purpose of this study is to compare the differences of neurodifferentiation potentials of SHED and SCAP. Materials and Methods：We cultivated SHED and SCAP in neural induction medium for 0 day, 1 day ,3 days, 7 days , 14 days and 21 days and analyzed cell morphology, cell proliferation, gene expression patterns(RT-PCR) and immunofluorescence before and after differentiation. Results：After 3 days cultivation in neural induction medium, the morphology of SHED and SCAP were changed to neuron like cells. We found that cell proliferation of SHED and SCAP were reduced. After 7 days cultivation in neural induction medium, gene expression patterns (RT-PCR) and Immunofluorescence analysis of the expression Neurofilament demonstrated that both SHED and SCAP were successfully differentiate into neuron cells. However, the Neurofilament gene expression of inducted SCAP was much upregulated then that of inducted SHED. This result indicated that the neurodifferentiation potential of SCAP is higher than that of SHED. Conclusion ：Although both SHED and SCAP have potentials for neurodifferentiation but neurodifferentiation potential of SCAP is much better than that of SHED. We can expect that by using SCAP for neurogenesis would get better results.