保康絲(柔沛)和雌激素在成年斑馬魚小腦創傷後的影響

The effect of finasteride and estradiol on adult zebrafish with traumatic cerebellum injury

王立旻(Wang, Li Ming)

指導教授 ： 莊永仁

國立清華大學/生命科學院/生物資訊與結構生物研究所/碩士(2016年)

摘要

中文摘要
性賀爾蒙已知在促進神經保護和神經再生中扮演重要的角色，但其作用機制和效果都還尚待釐清。在這項研究中，我們選擇斑馬魚作為主要模式生物，用來探討腦受創傷後複雜的修復過程。研究主要目的是分析性賀爾蒙如何調節成年斑馬魚於腦創傷後神經組織的修復與再生機制。在成年斑馬魚小腦由針穿刺產生外傷後，我們利用給予雌激素或以保康絲(柔沛; finasteride)抑制5α還原酶，調節實驗個體中性賀爾蒙的濃度與合成途徑。除了由組織切片染色追蹤修復過程，我們在創傷後的第3、6、和10天收取腦組織進行基因表現定量分析，藉以獲得目標基因的表現量變化數據。我們發現，經由保康絲(柔沛)的給予，神經再生的生物指標分子gfap和雌激素合成的關鍵酵素cyp19a1b mRNA表現量均被抑制。另一方面，雌激素的給予則會增加gfap和cyp19a1b mRNA的表現量。接著，我們分析了類固醇激素合成途徑的其它上游酵素的表達，包括cyp17和3β-hsd。出人意料的是，當給予保康絲(柔沛)後，斑馬魚小腦中cyp17和3β-hsd mRNA的表現量均出現顯著的增加，然而雌激素只會降低3β-hsd mRNA的表現量。這些結果意謂著雌激素可影響斑馬魚的神經再生且參與腦修復再生過程中的反饋調節機制。然而，如果抑制5α還原酶的活性，可能對腦的再生修復產生不利影響。類固醇合成酵素活性或表現量的調節，或有可能控制斑馬魚腦外傷後的神經修復再生。

關鍵字

腦創傷 ； 神經再生 ； 雌激素 ； 斑馬魚 ； 柔沛

並列摘要

Abstract
Sex hormones are known to play an important role in promoting neuroprotective activity and neurogenesis, but their roles and effects are not yet fully understood. Using zebrafish as a neurogenesis model organism, its brain serves as an excellent research system to study brain repair and the complex neurogenic process. In this study, we aimed to analyze how sex hormones regulate neurogenesis and brain regeneration after traumatic brain injury in adult zebrafish. After generating an injury by needle punch into the adult zebrafish cerebellum, we modified the sex hormonal level through estrogenic treatment or inhibition of 5α-reductase by finasteride treatment. At 3, 6 and 10 days post-injury, we harvested the fish brains for cell proliferation assay by histological analysis, and target gene expression profiling by qPCR assay. We found the mRNA expression level of neurogenesis biomarker gfap, and the key enzyme of estradiol synthesis cyp19a1b, were both down-regulated by finasteride. On the other hand, estradiol treatment increased mRNA expression of gfap and cyp19a1b. Next, we analyzed the expression of other upstream enzymes in the steroid hormone biosynthesis pathway, including cyp17 and 3β-hsd . Surprisingly, finasteride increased cyp17 and 3β-hsd mRNA expression, while estradiol treatment reduced 3β-hsd mRNA expression. The data suggests a feedback regulatory mechanism of estrogen during neurogenesis and brain regeneration. This study confirmed that estrogenic treatment can promote neurogenesis after traumatic brain injury in adult zebrafish. However, inhibition of 5α-reductase activity by finasteride may pose detrimental effect on brain regeneration. Altogether, we concluded that the regulation of steroidogenic enzymes may have a neurogenic switch mechanism on neurogenesis and after traumatic brain injury in zebrafish.

並列關鍵字

traumatic brain injury ； neurogenesis ； estrogen ； zebrafish ； finasteride

參考文獻

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