beta-lapachone在傷口癒合上的效應

Abstract

beta-lapachone，是由lapacho樹(Tabebuia avellanedae)樹皮中萃取出來的天然聚合物，目前已證實：在不同的濃度和條件下，beta-lapachone對癌症、發炎、病毒和寄生蟲有很好的抵抗性。但beta-lapachone對傷口癒合的影響則仍懸而未解，尚需要進ㄧ步的研究證實。本論文的研究目的就是探討 beta-lapachone是否能刺激不同的細胞生長及移行能力的效應、並且探究 beta-lapachone促進傷口癒合的過程機轉，進而討論 beta-lapachone作為傷口癒合促進藥劑的可能性。 傷口癒合是個相當複雜的過程，需要許多不同種類細胞的合作才能完成。在這樣的過程中，內皮細胞和纖維母細胞佔有非常重要的角色，他們負責產生新的細胞外基質，讓其他的細胞得以移動到傷口處生長，使傷口復原。在我們的實驗中，證實：(1) 低濃度的beta-lapachone確實可以增加細胞增生，包括有人類新生兒角質細胞(HEKn)、老鼠角質細胞(XB-2)、人類纖維母細胞(HS68)、老鼠纖維母細胞(3T3)、人類臍帶靜脈內皮細胞(HUVEC)及人類內皮細胞(EAhy926)；(2) beta-lapachone透過MAPK訊息傳遞路徑促進老鼠纖維母細胞(3T3)和人類內皮細胞(EAhy926)的增生和移行能力；(3) 不論在正常(C57BL/6)老鼠或是糖尿病(db/db)鼠身上，beta-lapachone都可以透過ERK 訊息傳遞路徑加速傷口的癒合。另外，beta-lapachone還可以刺激巨噬細胞分泌血管內皮生長因子(VEGF)和表皮生長因子(EGF)，這兩種生長因子對於許多種類細胞的生長都是非常有助益的。 全球糖尿病盛行率正以驚人的速度攀升，糖尿病儼然成為醫界之最大挑戰。糖尿病患者常受神經病變、傷口不易癒合、和全身感染之苦。對糖尿病患者來說，傷口癒合的延遲是ㄧ個很嚴重的問題，若能加速傷口癒合可以免除截肢的危險。 在本論文中，我們確認 beta-lapachone可以增加角質細胞、纖維母細胞和內皮細胞的增生；促進纖維母細胞和內皮細胞的移動能力；並且加速正常和糖尿病老鼠傷口癒合的過程。因此，beta-lapachone具有成為傷口癒合治療藥物的潛力，也許能成為臨床用藥。

Impaired wound healing is a serious problem for diabetic patients. Wound healing is a complex process that requires the cooperation of many cell types, including keratinocytes, fibroblasts, endothelial cells, and macrophages. beta-Lapachone, a natural compound extracted from the bark of the lapacho tree (Tabebuia avellanedae), is well known for its anti-tumor, anti-inflammatory, and anti-neoplastic effects at different concentrations and conditions, but its effects on wound-healing have not been studied. The purpose of the present study was to investigate the effects of beta-lapachone on the wound healing and its underlying mechanism. In this study, we demonstrated that a low dose of beta-lapachone enhanced the proliferation in several types of cells, including keratinocytes, fibroblasts, and endothelial cells, facilitated the migration of mouse 3T3 fibroblasts and human endothelial EAhy926 cells through different MAPK signaling pathways, and accelerated scrape-wound healing in vitro. Application of ointment with or without beta-lapachone to a punched wound in normal and diabetic (db/db) mice showed that the healing process was faster in beta-lapachone-treated animals than in those treated with vehicle only. In addition, beta-lapachone induced macrophages to release VEGF and EGF that are beneficial for growth of many cells. We also proved that ERK signal is indeed involved in the beta-lapachone-facilitated wound healing in vivo. Our results showed that beta-lapachone can increase the cell proliferation including keratinocytes, fibroblasts and endothelial cells and the migration of fibroblasts and endothelial cells and thus accelerate wound healing in vitro and in vivo. Therefore, we suggest that beta-lapachone may have potential for therapeutic use for wound healing.