三聚氰胺對類巨噬細胞RAW264.7、BV-2及人類胚胎腎臟細胞HEK293之發炎反應研究

Inflammatory Responses of Melamine on Macrophage-like Cells (RAW264.7 and BV-2) and Human Embryonic Kidney 293 Cells

吳幸儒(Sing-Ru Wu)

指導教授 ： 羅怡卿

高雄醫學大學/醫學院/藥理學科研究所/碩士(2009年)

摘要

三聚氰胺 (melamine)是工業上用來製造美耐皿樹脂(melamine resins)的原料。目前為止，關於三聚氰胺的毒性研究並不多，但是有些研究指出過量的三聚氰胺會引起動物或人類的腎臟疾病。2008年在中國含三聚氰胺的嬰兒奶粉導致嬰兒死亡，因此引起國際間重視三聚氰胺在食品上的污染。過去的研究指出三聚氰胺會造成動物結石的產生，進而導致腎臟的發炎及癌化，但三聚氰胺引起的發炎作用尚不明確。本研究將使用兩種類巨噬細胞株(macrophage-like cell lines)， 鼠科巨噬細胞RAW264.7和鼠科小神經膠細胞BV-2，以及人類胚胎腎臟細胞HEK293來進行研究三聚氰胺的發炎反應。實驗中所使用的三聚氰胺濃度為1pM,1nM,1 microM,10 microM,100 microM。結果顯示，三聚氰胺處理的RAW264.7和BV-2細胞，I kappa B alpha 的ser-32上有磷酸化的情形，I kappa B alpha 之降解增加及細胞核中NF-kappa Bp65的表現有明顯的增加。三聚氰胺亦會增加RAW264.7細胞COX-2的表現以及增加細胞所釋放的PGE2。在HEK293中，發現三聚氰胺亦可使I kappa B alpha 在ser-32上有被磷酸化的情形產生, 增加I kappa B alpha 有降解及增加細胞核中NF-kappa Bp65的表現；三聚氰胺會使HEK293細胞中COX-2表現上升。以上結果顯示COX-2及NF-kappa B訊號在三聚氰胺引起的類巨噬細胞株及HEK293細胞發炎反應扮演重要的角色。

關鍵字

三聚氰胺 ； 發炎

並列摘要

Melamine is an industrial chemical in the production of melamine resins.To date, there are still few studies about the toxic effects of melamine, but excessive exposure in animal or human causes kidney disease. At 2008, at least six deaths from presumed exposure to melamine in infant formula have been reported in China, leading international attention on the contamination of food with melamine. Previous studies indicate that melamine exposure insults stone formation, which induce inflammation and carcinogenesis in kidney. However, its inflammatory mechanisms remain unclear. In this study, we investigated the inflammatory effects of melamine on macrophage-like cell lines, RAW 264.7 and BV-2, and human embryonic kidney 293 cell line. The used concentrations of melamine are from 1 pM, 1 nM, 1 microM, 10 microM and 100 microM. We found that melamine phosphorylated I kappa B alpha at ser-32, and it increased I kappa B alpha degradation and NF-kappa Bp65 expressions in RAW264.7 and BV-2 cells. Furthermore, melamine up-regulated COX-2 expression and increased PGE2 levels. In HEK293 cells, melamine also increased phosphorylated I kappa B alpha, I kappa B alpha degradation and expression of NF-kappa Bp65 and COX-2. In conclusion, the present results suggest that COX-2 and NF-kappa B signals play important roles in melamine-induced inflammatory responses in macrophage-like cells and HEK293 cells.

並列關鍵字

melamine ； inflammation

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