斑馬魚顆粒蛋白前體調控肝臟再生之機制

Abstract

肝臟的生長除了於胚胎發育階段，另可發生於肝臟受到損傷時所啟動的肝臟再生 機制。本實驗室先前的研究指出，顆粒蛋白前體藉由調控肝細胞生長因子接受器 訊息傳遞路徑進而影響肝細胞生長。顆粒蛋白前體為一種具有多功能性的分泌性 醣蛋白，已知參與在細胞生長、傷口癒合、腫瘤形成、發炎反應、神經發育及在 神經退化性疾病等方面並扮演重要的角色。本研究欲探究顆粒蛋白前體參與在肝 臟再生中所扮演之角色，使顆粒蛋白前體在肝臟生長發育的調控功能更完整。我 們選用斑馬魚建立肝臟再生的模式魚種，將肝臟專一性表現螢光的成魚進行部分 肝切除手術，觀察顆粒蛋白前體是否會參與在肝臟再生中。利用定量聚合酶連鎖 反應的結果顯示，在肝臟受到損傷後，此顆粒蛋白前體的訊息核糖核酸表現量及 細胞週期、細胞增生相關基因群會伴隨肝臟再生的過程而被誘發表現。為了探究 顆粒蛋白前體A 型在斑馬魚肝臟再生中的調控功能。我們分別利用基因功能失活 及增益方法探究之。我們的實驗結果顯示，顆粒蛋白前體A 型失活的斑馬魚在部 分的肝臟切除手術之後，肝臟表現出較弱的肝臟再生的恢復能力，造成此結果的 原因是細胞週期相關的基因延遲的表現，且細胞增生相關的基因表現受到了抑制， 這些受影響的基因表現在肝臟切除受術後三十六小時可明顯的觀察到。在另一方 面，我們肝臟專一性增益表現顆粒蛋白前體A 型的斑馬魚，在部分的肝臟切除手 術後，肝臟表現較快的肝臟再生的恢復能力。因此，我們推斷斑馬魚顆粒蛋白前 體A 型藉由調控肝細胞生長因子接受器訊息傳遞路徑對肝臟再生是必須的。

Physiologic liver growth not only occurs in embryonic development, but also in the liver regeneration process that was activated after liver injury. According to our previous research, it indicated that progranulin could modulate MET, the receptor of hepatocyte growth factor, signaling to regulate liver growth. Progranulin is a multifunctional secreted glycoprotein. It has been known that plays a critical role in cell growth, wound healing, tumorigenesis, inflammation response, neurodevelopment, and neurodegeneration. This research would study the regulatory role of progranulin that involve in liver regeneration. We established a liver regeneration model after partial hepatectomy in liver-specific fluorescent adult zebrafish. The result of quantitative-PCR showed that mRNA expression of progranulin, cell cyele and proliferation related genes were induced after partial hepatectomy. To study the functional progranulin A in liver regeneration. We use the loss of function and gain of function assay. In our grnA morphant showed a weak recovery with delayed cell cycle related gene and suppressed cell proliferation related gene that specifically at 36 hours after partial heapatectomy. On the other side, in our liver specific grnA over expression transgenic zebrafish showed a faster recovery than wild-type zebrafish after partial hepatectomy. In conclusion, grnA mediate met signaling is required for liver regeneration.