斑馬魚是目前生命科學(xué)研究中重要的模式脊椎動物之一,。由于斑馬魚基因與人類基因的相似度達(dá)到87%,,這意味著在其身上做藥物實(shí)驗(yàn)所得到的結(jié)果在多數(shù)情況下也適用于人體,因此它受到生物學(xué)家的重視,。不同于哺乳動物,,斑馬魚在成年以后也會生產(chǎn)出新的運(yùn)動神經(jīng)元。由于這一特征,,斑馬魚研究運(yùn)動神經(jīng)元是如何產(chǎn)生的機(jī)制過程中占有重要地位,。
運(yùn)動神經(jīng)元即外導(dǎo)神經(jīng)元是負(fù)責(zé)將脊髓和大腦發(fā)出的信息傳到肌肉和內(nèi)分泌腺,支配效應(yīng)器官的活動的神經(jīng)元,。運(yùn)動神經(jīng)元我們?nèi)粘Uf話,、行走以及呼吸是很重要的,我們機(jī)體產(chǎn)生運(yùn)動神經(jīng)元主要是在胚胎發(fā)育階段,,胚胎分娩以后運(yùn)動神經(jīng)元就不在繼續(xù)產(chǎn)生了,。由于這種非可再生性,一旦我們罹患了運(yùn)動神經(jīng)元疾病,、中風(fēng)或是脊髓損傷等疾病的話,,運(yùn)動神經(jīng)元會損傷機(jī)體不能再生。
目前,,愛丁堡大學(xué)研究人員已經(jīng)能在模式動物斑馬魚中操控(控制)那些主要調(diào)控肌肉運(yùn)動的一些神經(jīng)元的生成過程,。并在The Journal of Neuroscience 上發(fā)表了其最新研究結(jié)果,研究人員在成年斑馬魚體內(nèi)通過藥物的干預(yù)能夠抑制Notch信號通路,,進(jìn)而增加了斑馬魚體內(nèi)運(yùn)動神經(jīng)元的產(chǎn)生,。
該研究主要集中在斑馬魚體內(nèi)的干細(xì)胞上(形成運(yùn)動神經(jīng)元的能力很強(qiáng)大),而研究發(fā)現(xiàn)斑馬魚Notch1蛋白表達(dá)升高會抑制干細(xì)胞向運(yùn)動神經(jīng)元細(xì)胞的分化,。這一結(jié)果提示抑制Notch1蛋白的表達(dá)有可能會增加斑馬魚體內(nèi)干細(xì)胞分化成運(yùn)動神經(jīng)元,。
這一最新研究結(jié)果有助于科研人員尋找出新的治療手段,,治愈那些罹患運(yùn)動神經(jīng)元疾病、脊髓損傷或是中風(fēng)癥的患者,。(生物谷Bioon.com)
doi:10.1523/JNEUROSCI.6398-11.2012
PMC:
PMID:
Notch Signaling Controls Generation of Motor Neurons in the Lesioned Spinal Cord of Adult Zebrafish
Tatyana B. Dias,Yu-Jie Yang,Kazuhiro Ogai,Thomas Becker*, and Catherina G. Becker*
In mammals, increased Notch signaling is held partly responsible for a lack of neurogenesis after a spinal injury. However, this is difficult to test in an essentially nonregenerating system. We show that in adult zebrafish, which exhibit lesion-induced neurogenesis, e.g., of motor neurons, the Notch pathway is also reactivated. Although apparently compatible with neuronal regeneration in zebrafish, forced activity of the pathway significantly decreased progenitor proliferation and motor neuron generation. Conversely, pharmacological inhibition of the pathway increased proliferation and motor neuron numbers. This demonstrates that Notch is a negative signal for regenerative neurogenesis, and, importantly, that spinal motor neuron regeneration can be augmented in an adult vertebrate by inhibiting Notch signaling.