2011-08-012024-05-13https://scholars.lib.ntu.edu.tw/handle/123456789/649390摘要：芳香族氨基酸脫羧酶(AADC)缺乏症為兒童神經傳導物質疾病之一，在近幾年益顯其重要性。雖然AADC 缺乏症在西方國家的病例並不多，在台灣AADC 缺乏症的案例相對常見。過去幾年我們也發現了一些與國外不同的異常基因突變，這顯示了AADC 缺乏症在台灣可能是一種重要但常被誤的神經退化性疾病。我們這幾年的臨床研究也顯示，AADC 缺乏症的病人大腦腦室擴大和低髓鞘化的比例很高，顯示AADC 缺乏會導致神經細胞的分化受影響。由於目前全世界並沒有一個好的動物模式，所以此研究的目標之一就是希望建立AADC 缺乏症的動物模式。過去幾年我們在國科會計劃的支持下進行AADC 缺乏症小鼠模式的建立，預計尚需1-2年才會完成，在本研究中我們希望另外利用AADC 缺乏斑馬魚模式的建立，來探討AADC 缺乏症導致發展遲緩的致病機轉，也探討AADC 缺乏對神經細胞分裂與分化的影響。由於斑馬魚模式可更進一步觀察到早期神經系統發育的影響，我們希望兩種動物模式的建立有互補的作用，使AADC 缺乏症的致病機轉更為清楚。在本研究中我們希望利用AADC抑制劑和morpholino antisense oligos的方式，產生AADC 缺乏斑馬魚模式。也會利用注射與病人相同基因突變的vector，探討台灣特有的AADC突變是否也對神經細胞的分裂與分化有負面的影響。研究中我們會利用不同方式(包括染色、西方點墨法、PCR、in situ hybridization、電生理、和行為的檢測)，探討AADC缺乏對神經細胞分裂與分化的影響。我們也將利用蛋白質體學的方式與microarrayanalysis的方式，分析AADC抑制劑或morpholino antisense oligos處理後，對基因與蛋白質表現的影響，更進一步利用PC12細胞和神經幹細胞探討，希望因而發現新的作用機轉。在我們目前的國科會計劃，我們發現AADC 缺乏會影響神經幹細胞的細胞大小與分裂。因此此研究的另外目標之一就是找出可能的機轉，是否與mTOR或PTEN路徑有關。在本研究中我們也希望建立一藥物篩檢的平台，利用AADC 缺乏斑馬魚模式篩檢可能有效的藥物，並在未來於AADC缺乏症小鼠模式驗證是否真的有效。AADC 缺乏斑馬魚模式也會用來探討目前的治療藥物是否對這些孩童有所幫助。AADC 缺乏斑馬魚模式所發現的基因改變，在1-2年後AADC 缺乏症小鼠模式建立完成後，也會進一步加以驗證。我們希望將來國內AADC 缺乏症孩童不再被誤診為腦性麻痺，且這些孩童也能夠得到較好的治療。<br> Abstract: Aromatic L-amino acid decarboxylase (AADC) deficiency is not an uncommonneurometabolic disease in children. Compared with that in western countries, the prevalenceof AADC deficiency in Taiwan is much higher. It indicates that AADC deficiency may be animportant, but underdiagnosed neurometabolic disease in Taiwan. Under the support ofongoing NSC project, we have found that AADC deficiency in Taiwan has a novel mutation(IVS6+4), and most patients have significant brain atrophy or hypomyelination in MRIexamination. Dopamine transporter imaging also revealed the downregulation of dopaminetransporters in striatum. To our interest, the expression of dopamine transporters seems to becorrelated with the prognosis of the patients. Therefore, to clarify the effect of AADCdeficiency on neurons, a good animal model is mandatory.In the present study, two different types of animal models will be used for theinvestigation of AADC gene function, and the effect of AADC deficiency on neuronaldifferentiation. The reasons why we want to use two different animal models are that thezebrafish is much easier to be manipulated with in comparison with mouse model. Thedifferentiation of zebrafish is much faster than that of mouse, and we can get more solid datain a short period. Furthermore, the zebrafish model may be more suitable to be used in drugscreening than mouse model.We have been generatingAADC knockout mice under the grantsupport from National Science Council in Taiwan, and it may also take more than 1-2 years tobe finished. Meanwhile, we also have generated another animal model using zebrafish.Therefore, in the first part of the present study, we will use zebrafish model to investigate theeffect of AADC knowkdown on neuronal differentiation, and potential alterations of proteinor gene expression (by microarray and proteomics approach). Because our preliminary datahave shown that knockdown of AADC in rat neural stem cells will decrease the proliferationand cell size of the stem cells, we also want to investigate whether the changes of cellproliferation and cell size is related to PTEN or mTOR pathway.We also want to generate aplatform for screening of drugs with potential therapeutic effect using zebrafish model. Drugswith potential therapeutic efficacy will then be investigated in knockout mice.We also want toinvestigate whether knockdown of AADC gene will make the neurons prone to have electricfiring as in our preliminary data. Finally, knockout mouse model will be used in the secondpart of the study to investigate whether the change of proteins or genes on zebrafish will alsodevelop in mouse model.We will use mouse model in the future for gene therapy study, andother microarray study. We hope that the pathogenic mechanisms of brain atrophy in patientswith AADC deficiency can be clarified leading to better care and treatments of patients.神經發育芳香族氨基酸脫羧?斑馬魚