Martins de Lima Thais, Cury-Boaventura Maria Fernanda, Giannocco Gisele, Nunes Maria Tereza, Curi Rui
Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, CEP 05508-900, São Paulo, Brazil.
Clin Sci (Lond). 2006 Nov;111(5):307-17. doi: 10.1042/CS20060064.
In the present study, the cytotoxicity of palmitic, stearic, oleic, linoleic, arachidonic, docosahexaenoic and eicosapentaenoic acids on a macrophage cell line (J774) was investigated. The induction of toxicity was investigated by changes in cell size, granularity, membrane integrity, DNA fragmentation and phosphatidylserine externalization by using flow cytometry. Fluorescence microscopy was used to determine the type of cell death (Acridine Orange/ethidium bromide assay). The possible mechanisms involved were examined by measuring mitochondrial depolarization, lipid accumulation and PPARgamma (peroxisome-proliferator-activated receptor gamma) activation. The results demonstrate that fatty acids induce apoptosis and necrosis of J774 cells. At high concentrations, fatty acids cause macrophage death mainly by necrosis. The cytotoxicity of the fatty acids was not strictly related to the number of double bonds in the molecules: palmitic acid>docosahexaenoic acid>stearic acid=eicosapentaenoic acid=arachidonic acid>oleic acid>linoleic acid. The induction of cell death did not involve PPARgamma activation. The mechanisms of fatty acids to induce cell death involved changes in mitochondrial transmembrane potential and intracellular neutral lipid accumulation. Fatty acids poorly incorporated into triacylglycerol had the highest toxicity.
在本研究中，研究了棕榈酸、硬脂酸、油酸、亚油酸、花生四烯酸、二十二碳六烯酸和二十碳五烯酸对巨噬细胞系（J774）的细胞毒性。通过使用流式细胞术检测细胞大小、粒度、膜完整性、DNA片段化和磷脂酰丝氨酸外化的变化来研究毒性诱导情况。使用荧光显微镜确定细胞死亡类型（吖啶橙/溴化乙锭检测）。通过测量线粒体去极化、脂质积累和PPARγ（过氧化物酶体增殖物激活受体γ）激活来检查可能涉及的机制。结果表明，脂肪酸可诱导J774细胞凋亡和坏死。在高浓度下，脂肪酸主要通过坏死导致巨噬细胞死亡。脂肪酸的细胞毒性与分子中的双键数量并不严格相关：棕榈酸>二十二碳六烯酸>硬脂酸=二十碳五烯酸=花生四烯酸>油酸>亚油酸。细胞死亡的诱导不涉及PPARγ激活。脂肪酸诱导细胞死亡的机制涉及线粒体跨膜电位的变化和细胞内中性脂质的积累。难以掺入三酰甘油的脂肪酸具有最高的毒性。
