泡沫细胞形成与胞浆Ca^(2+)水平变化

Foam cell formation and intracellular Ca^(2+) alteration

目的 :探讨巨噬细胞在泡沫化过程中 ,胞浆Ca2 +水平的变化规律及其病理机制。方法 :选择动脉粥样硬化易感性C5 7BL/ 6J小鼠 ,取其腹膜巨噬细胞 ,在 10mg·L-1氧化低密度脂蛋白中孵育 96h ,制备了富含脂质成分的泡沫样细胞。在此基础上 ,应用Ca2 +荧光指示剂技术和NADH氧化偶联差光谱变化的分析方法 ,检测了前述泡沫样细胞的胞浆Ca2 +水平及膜成分Ca2 +-ATP酶活性。结果 :泡沫样细胞的胞浆Ca2 +水平是对照巨噬细胞的 2 7倍 ,膜成分Ca2 +-ATP酶活性为后者的 2 4 %。结论 :在巨噬细胞源性泡沫细胞的形成过程中 ,伴随着缓慢的膜外Ca2 +内流或肌质网Ca2 +释放 ,这可能与初期膜上Ca2 +通道的持续性开放及后期膜上Ca2 +泵功能的不可逆性钝化有关。

AIM: These studies aimed at exploring the alteration of intracellular Ca 2+ level in the course of macrophage-derived foam cell formation as well as its mechanism.METHODS: Foam-like cell was generated by peritoneal macrophage of C57BL/6J mouse, which is susceptible to atherosclerosis, incubated in 10 mg·L -1 oxidized low density lipoprotein for 96 hours. With the technique of Ca 2+ fluorescent indicator and the assay of NADH-oxidizing coupling spectrum-alteration, the intracellular Ca 2+ level and membranous Ca 2+ -ATPase activity of the above foam-like cell were determined.RESULTS: The foam-like macrophage Ca 2+ level was 2.7 times higher than the control macrophage, and the former Ca 2+ -ATPase activity was 24% of the later.CONCLUSION: The results suggested that macrophage-derived foam cell formation was connected with slow Ca 2+ entry or release, which possibly derived from long lasting opening of membranous Ca 2+ channels at the early stage and irreversible inactivating of membranous Ca 2+ pump at the late stage.