本計畫的主要目的為藉由陽離子性高分子非病毒性載體之特性、結合細胞吞噬相關 基因之質體所建構之高分子基因傳遞系統，能調控細胞自我吞噬之運作進而能廣泛地應 用於臨床之運用與開發。本計畫預計第一年將運用陽離子性高分子傳送 Atg 基因以調控 細胞自我吞噬之功能。我們將利用 MEF 老鼠胚胎纖維母細胞株 (Wild-type 及 Atg5−/− 基因 (Atg 5 剔除基因)) 來當作一個正常與缺乏細胞自我吞噬作用之細胞模式，然後將 陽離子性高分子將帶有 Atg 5 基因質體分別輸送至 wild-type 及 Atg5−/− MEF 細胞內， 嘗試來恢復或增加其細胞自我吞噬功能與探討自我吞噬在陽離子性高分子細胞死亡機 轉上所扮演之親死亡或保護角色。然後第二年將探討陽離子性高分子之胺基緩衝能力如 何影響細胞自我吞噬之作用，我們將評估細胞自我吞噬蛋白質表現情形如何受陽離子性 高分子之影響，並探索高分子是否參與溶酶體與自我吞噬體之融合、或者是單純以其緩 衝能力去影響溶酶體之 pH 及分解酵素之運作。最後，第三年本計畫將以特別針對細胞 自我吞噬與細胞凋亡所設計之生物晶片，來探討陽離子性高分子及複合體如何全面性地 影響細胞自我吞噬與細胞凋亡相關基因之表現情形，並進而了解陽離子性高分子細胞毒 性機轉中細胞自我吞噬與細胞凋亡相互之交叉分子作用與特定路徑。 The aim of this project is to develop polymeric gene delivery systems that fully facilitate the characteristics of cationic polymers as non-viral vectors for delivering related autophagic genes for regulating autophagic process for clinical applications and developments. At first year, we will apply cationic polymers for delivering autophagic Atg genes to regulate autophagic functions. Wild-type and atg5−/− mouse embryonic fibroblast (MEF) cell lines will be selected as cell models that represent the cells with normal autophagic functions and the cells with lacking of atg5 gene. Then, cationic polymers will deliver atg5 gene into MEF cells to restore or increase the function of autophagy and explore the role of autophagy that either protective or enhanced cell death induced by cationic polymers. At second year, we will investigate how the amine buffering capacity of cationic polymers affects the function of autophagy. Also, we will evaluate the effect of cationic polymers on autophagic protein expressions and explore if cationic polymers involve in the fusion between lysosome and autopagsome or just affect the pH of lysosome and the proteolytic function of enzymes. Finally, at third year we will analyze the wholly gene expression profiles in MEF cells induced by cationic polymers and its DNA complexes by distinctive microarray that emphasizes the related autophagic and apoptotic genes. We will expect to understand the exact molecular mechanism and specific pathway of cell death, and the interactions between autophagy and apoptosis induced by cationic polymers.
