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The Caspase Pathway of Linoelaidic Acid (9t, 12t‐C18:2)‐Induced Apoptosis in Human Umbilical Vein Endothelial Cells
Author(s) -
Bin Qiu,
Rao Huan,
Hu JiangNing,
Liu Rong,
Fan YaWei,
Li Jing,
Deng ZeYuan,
Zhong Xianfeng,
Du FangLing
Publication year - 2013
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/s11745-012-3728-4
Subject(s) - umbilical vein , apoptosis , lipidology , clinical chemistry , chemistry , caspase 3 , human umbilical vein endothelial cell , caspase 9 , biochemistry , microbiology and biotechnology , in vitro , biology , programmed cell death
Trans fatty acids (TFA) are reported to contribute to inflammation and coronary heart disease. The study aim was to investigate the proapoptotic effects of two double bond TFA (TDTFA) on human umbilical vein endothelial cells (HUVEC). The HUVEC were grown in media supplied with linoelaidic acid (9t,12t‐C18:2) at 50, 100, 200, 400 μmol/l for 24 or 48 h to examine the effects of TDTFA on the viability and apoptosis of these cells. Flow cytometry analysis and confocal scanning were used to measure apoptosis, cell binding of Annexin V and propidium iodide uptake. Colorimetric assay and RT‐PCR were used to analyze enzyme activities and mRNA expression of caspase‐3, ‐8 and ‐9 in HUVEC. Results showed that 9t,12t‐C18:2 inhibited the viability of HUVEC in a dose‐dependent and time‐dependent manner. The percentages of 9t,12t‐C18:2 induced apoptotic and necrotic cells significantly increased compared with that of the control. The activities and mRNA expression of caspase‐8, ‐9 and ‐3 were significantly increased in 9t,12t‐C18:2 treated cells compared to that of the control. Addition of specific inhibitors of caspase‐8 (z‐IETD‐fmk) and caspase‐9 (z‐LEHD‐fmk) to HUVEC was found to completely inhibit 9t,12t‐C18:2‐induced activation of caspase‐3, and z‐IETD‐fmk inhibited the activation of caspase‐9. Meanwhile, it was found that mRNA expression of Bid, Smac/DIABLO and the release of mitochondrial cytochrome c were significantly elevated by 9t,12t‐C18:2 treatment. These results suggest that 9t,12t‐C18:2 may induce apoptosis of HUVEC through activating caspase‐8, ‐9 and ‐3. Both the death receptor pathway and the mitochondrial pathway may be involved in the apoptosis induced by 9t,12t‐C18:2.