靜磁場對於 PC12 類神經細胞之神經生長影響
The Influence of Static Magnetic Field on Neuronal Outgrowth of PC12
cells
中文摘要 先前的研究指出，給予脈衝式電磁場刺激可以用於治療對於神經受到損傷的中風 和腦挫傷病患。它可以提供一個局部性的治療神經再生刺激源，且對於病患是一 個有潛力的非侵入性物理治療方式。近年來，不同於脈衝式電磁場的靜磁場，亦 被發現具有刺激原骨母細胞成熟分化的作用。本實驗是嘗試使用靜磁場做非侵入 性的物理性刺激源以探討其促進神經再生的可能性與機轉。實驗方法上，PC12 細胞先以25 ng/ml 及 50 ng/ml Nerve growth factor (NGF)預先處理，以 誘使其分化成具有神經細胞特徵的模型。然後將已被誘導分化的細胞連續暴露於 4000 高斯的靜磁場 15 天。細胞的形態則以光學顯微鏡觀察，並在時間點為 5 天、10 天、15 天時進行拍照與觀察，經由比較已分化的 PC12 細胞及未經 NGF 處理的PC12 細胞在暴露或未暴露靜磁場情形下，三者之間的神經樹突長度與分 支情形，以期瞭解靜磁場對神經分化的可能作用。在初步的結果中，我們發現由 NGF 所誘導的已分化 PC12 細胞，在暴露於靜磁場之後 10 天，其神經纖維長 度均大於1 倍、2 倍與 3 倍之細胞直徑之出現比例，分別為 94.84±4.51%、 74.05±13.09%及 57.04±6.45%均較未經靜磁場處理的細胞(其比例分別為 74.76±5.16%、48.52±8.48%及 31.59±11.75%)明顯來得大(p<0.05)， 且更具單一方向性，此結果顯示靜磁場具有影響神經纖維分化之第二個階段的可 能性，即具有促進延長神經纖維生長的作用。基於此本研究認為，以靜磁場作為 神經再生或促進分化作用具有可行性，並值得繼續深入探討。 英文摘要Previously investigations indicated that pulse electromagnetic field (PEMF) can be a neuroregenerative stimulator for stroke and traumatic injuring patients. It can be a local healing stimulator for nerve regeneration and has potential to become a
non-invasive physical therapeutic tool for these patients. Recently, it was found that, similar to PEMF, static magnetic field (SMF) can promote osteoprogenitors
differentiate into mature phenotype. Accordingly, in this study proposal, we hypothesize that SMF can also be a non-invasive stimulator to promote nerve regeneration. To test this hypothesis, PC12 cells were carried out for in vitro experiments. The cells were pre-induced to express neural characteristics with 25 ng/ml and 50 ng/ml nerve growth factor (NGF). Then the induced cells were
continuously exposed to 4000G SMF for 15 days. Cell morphologies were observed by optical microscope at 5, 10 and 15 days after SMF treatment. The images of the
cells were recorded by a digital camera at the observation times. In addition, we compared the morphology changes of the differentiated PC12 cells treated with and without SMF exposure by counting the length and branching degree of dendrites. Our preliminary results showed that SMF-treatment has neurite-elongation effect in the NGF-induced PC12 cells. These results suggest that the SMF may affect
neurogenerative process at the second stage, i.e, neurite elongation. When the cells were exposed to SMF, the population of the cells extending neurites of length more than once, twice and thrice the cell diameter, the datum were 94.84±4.51%、74.05± 13.09% and 57.04±6.45%, respectively. However, the analogous value of the
unexposed cells of the different multiple were taken into account, these results were significantly reduced to 74.76±5.16%、48.52±8.48% and 31.59±11.75% So, base on these findings, additional experiments on the mechanism of such effect should be valuable for more insight into the application of SMF-induced nerve regeneration or nerve differentiation.
