| Abstract: | 衛生褔利部的調查報告指出，國人因肺炎相關疾病引發死亡案例約佔所有病因死 亡率的 40%。其中，急性肺損傷為常見且嚴重急症，可惡化成急性呼吸窘迫症候群，引 發多重器官衰竭，增加死亡風險。細菌性感染則是誘發急性肺損傷的主因之一。急性肺 損傷的組織病理變化為嗜中性球浸潤、肺血管滲透性增加、肺壁增厚、肺水腫、玻璃膜 形成等。過程中，嗜中性球的浸潤活化扮演著關鍵角色。活化的嗜中性球會產生趨化、 吞噬、去顆粒、呼吸爆發、胞外殺菌誘補網的作用，適度的嗜中性球活化可毒殺入侵細 菌，但過度的活化則會傷害週邊正常組織，引發急性肺損傷及相關併發症。對於急性肺 損傷的治療目前多以支持療法為主，並無有效的藥物可用。球薑酮 (zerumbone) 為薑科 植物紅球薑的主成分之一。紅球薑為日常生活中常用的香料或調味料，於傳統醫學上主 要用於袪風散寒、溫中止痛、肺寒咳嗽等作用。近年來的研究證實，球薑酮具有抗癌、 抗發炎、抗氧化、抗菌的功效。其中巨噬細胞及嗜中性球可能是球薑酮抗發炎的作用標 的細胞。臨床觀察及動物研究發現，抑制嗜中性球的過度浸潤活化，可有效緩解急性肺 損傷及相關併發症。因此，球薑酮可能是開發預防治療急性肺損傷的潛在藥物。透過脂 多醣體誘發小鼠急性肺損傷動物模式初步發現，球薑酮可改善急性肺損傷的肺組織病理 變化、嗜中性球浸潤、發炎細胞激素表現，過程中伴隨著 NF-B 及 Akt 活性的抑制。 相關研究顯示，PI3K/Akt路徑在急性肺損傷過程調控嗜中性球浸潤活化及發炎細胞激素 表現。我們推論，嗜中性球是球薑酮急性肺損傷保護作用的關鍵細胞，球薑酮可能透過 干擾 PI3K/Akt 路徑來抑制嗜中性球浸潤活化及發炎細胞激素表現，進而降低急性肺損 傷傷害。這個假說將透過小鼠動物急性肺損傷模式與 HL60細胞分化類嗜中性球細胞模 式來驗證。全程的研究計畫實驗過程將依序探討下面三個議題重點來回答整體研究計畫 的目標：包括一、於脂多醣體誘發急性肺損傷動物模式中，評估球薑酮的保護功效，著 重於 PI(3,4,5)P3生合成、Akt活性及 PI3K/Akt所調控的生物活性及功能；二、於脂多醣 體誘發急性肺損傷動物模式中，評估球薑酮的 PI3K/Akt 調控機制；三、於過度表現 PI3K/Akt上游 Ras-p110及 GEF的 HL60細胞分化類嗜中性球細胞模式中，評估球薑酮 的嗜中性球細胞 PI3K/Akt路徑調控特性。
According to the investigation of Ministry of Health and Welfare, Taiwan, the death of pulmonary inflammation-related diseases is about 40%. Among them, acute lung injury (ALI) and its more severe form, acute respiratory distress syndrome (ARDS), can lead to multiorgan failure and increase mortality rate. Bacteria infection is a major cause of ALI. The pathological hallmarkers of ALI include polymorphonuclear leukocytes (PMN) infiltration, lung vascular permeability elevation, lung edema, thickness of the alveolar wall, and hyaline membrane formation. During the pathological course, the activation of PMN plays a crucial role. Activated PMN show increased chemotaxis, phagocytosis, degranulation, respiratory burst, and neutrophil extracellular traps. Appropriate PMN activation detsroys invaded bacteria and prevents bacteria-related complications. Unfortunately, overactivated PMN damages normal tissues and causes ALI and associated complications. Currently, there is no effective therapeutic or protective agent for the treatment of ALI but supporting care. Zerumbone is main compoment of Zingiber zerumbet, which are widely used as spices, flavouring agents, and medicines in tranditional medicine. Zingiber zerumbet usages as botanical mdeicine include treatment of inflammation, fever, toothache, indigestion, constipation, diarrhea, severe sprains, and to relieve pain, as well as antispasmodic, antirheumatic, and diuretic agents. Zerumbone, an active component of Zingiber zerumbet is demonstrated to be of anticancer, antiinflammation, antioxidation, and antibacteria activities. Macrophages and PMN are potential targeted cells for the antiinflammatory responses of zerumbone. Clinical observations and animal studies reveal that the inhibition of PMN infiltration and activation is a beneficial stretgy to treat ALI and associated complications. Thus, zerumbone might be of potential to be developed as a therapeutic agent for the treatment of ALI. Through lipopolysaccharide-induced ALI mice model, zerumbone improved ALI-induced histological alterations, PMN infiltration, and proinflammatory cytokine overproduction. The beneficial effect was accompanied by the inhibition of NF-B and Akt. Relevant studies show that PI3K/Akt molecule and related action networks play a crucial role in regulating PMN infiltration, activation, and proinflammatory cytokine expression and ALI. Together with these findings, we hypothesized that PMN might be a action target of beneficial effects of zerumbone against ALI. Particularly, zerumbone might interfere PI3K/Akt cascades to downregulate PMN infiltration, activation, and proinflammatory cytokine expression and finally lead to improvement of ALI. This hypothesis will be verified by acute ALI mice model and HL60-differentiated PMN-like cell model. Following three specific aims will be addressed: (1) to delineate the effects of zerumbone on PI(3,4,5)P3 accumulation and Akt activity as well as PI3K/Akt downstream PMN biological activities in lipopolysaccharide-induced ALI mice model; (2) to delineate the effect of zerumbone on PI3K/Akt upstream regulatory machinary in lipopolysaccharide-induced ALI mice model; (3) to delineate the effect of zerumbone on the regulation of PI3K/Akt activity in Ras-p110- and GEF-overexpressed HL60-differentiated PMN-like cells. |
