子宮24p3蛋白誘發子宮內膜細胞凋亡之研究

Abstract

24p3蛋白屬於疏水性分子結合蛋白，為小白鼠動情週期中子宮外泌蛋白之一。實驗室近期研究指出小鼠子宮24p3蛋白可以透過cytochrome c的釋放以及活化caspase 3造成人類子宮內膜細胞的凋亡，顯示24p3蛋白於雌性生殖系統中可能扮演重要角色。為了解24p3於生殖系統中誘發細胞凋亡的機制，利用純化自小鼠子宮的24p3蛋白以及人類子宮內膜細胞為模式研究誘發細胞凋亡過程中參與反應之因子，發現24p3蛋白於無血清狀態下可透過NADPH oxidase造成胞內氧化壓力增加並可能藉此調節MAPK蛋白磷酸化狀態及造成胞內鈣離子濃度的改變，暗示MAPK蛋白的磷酸化狀態與鈣離子濃度的增加可能與細胞的死亡有關，此過程中p53、bcl-2、bax等基因表現並未受到調節。推測24p3蛋白透過不同於Bcl-2/Bax之凋亡路徑促成細胞凋亡。

24p3 protein, a lipocalin, is one of the secretory proteins during mouse estrous cycle. According to the data of our laboratory, reveals that 24p3 protein induces apoptosis of human endometrial carcinoma cell line via releasing cytochrome c from mitochondria and activating caspases. These results suggest that 24p3 protein plays an unique role in female reproduction. To elucidate the mechanism of 24p3 protein induced apoptosis in reproduction system, mice uterine 24p3 protein and human endometrial cell line (RL95-2) were used in this study. After treatment of RL95-2 cells, 24p3 protein creates an oxidative intracellular environment that may trigger the changes of MAPK activity and elevation of intracellular calcium via NAPDH oxidase. These data suggest that MAPK and calcium may be correlated to cell death. Without significant changes in mRNA levels of p53, bcl-2, and bax could be observed in 24p3 protein-treated cells. These findings revealed that the eliciting of cell physiological response by 24p3 protein in a novel pathway.