Zhao Yufeng, Zhang Lei, Yan Aili, Chen Di, Xie Rong, Liu Yingguang, Liang Xiangyan, Zhao Yanyan, Wei Lanlan, Yu Jun, Xu Xi, Su Xingli
The institute of Basic Medical Sciences, Xi'an Medical University, Xi'an, 710021, China.
Department of Gerontological Surgery, The First Affiliated Hospital, Xi'an Medical University, Xi'an, 710061, China.
BMC Pharmacol Toxicol. 2018 May 30;19(1):26. doi: 10.1186/s40360-018-0215-4.
Grifolic acid is a derivative of grifolin, an antitumor natural compound, and it was reported as an agonist of free fatty acid receptor GPR120. Little is known about its antitumor effects and the involvement of GPR120.
GH3 cells, the rat anterior pituitary adenoma cells, were cultured and the cell death was measured by MTT assay and Annexin V/PI staining. The mitochondrial membrane potential (MMP) of GH3 cells was measured by JC-1 staining. Cellular ATP levels and the intracellular NAD/NADH ratio were measured. GPR120 expression in GH3 cells was observed by RT-PCR and Western Blot, and siRNA was used to inhibit GPR120 expression in GH3 cells.
Grifolic acid dose- and time-dependently induced the necrosis of GH3 cells. Grifolic acid significantly reduced the mitochondrial membrane potential (MMP) and decreased cellular ATP levels in GH3 cells. In contrast, the MMP of isolated mitochondria was not decreased by grifolic acid. The intracellular NAD/NADH ratio was significantly increased by grifolic acid. GPR120 is expressed in GH3 cells, but GPR120 agonists such as EPA, GW9508 and TUG891 did not affect the viability of GH3 cells. Moreover, GPR120 siRNA knockdown showed no significant influence on grifolic acid-induced GH3 cell death.
Grifolic acid induces GH3 cell death by decreasing MMP and inhibiting ATP production, which may be due to the inhibition of NADH production through a GPR120-independent mechanism.
麦角硫因酸是抗肿瘤天然化合物麦角硫因的衍生物，据报道它是游离脂肪酸受体GPR120的激动剂。关于其抗肿瘤作用以及GPR120的参与情况知之甚少。
培养大鼠垂体前叶腺瘤细胞GH3，通过MTT法和Annexin V/PI染色检测细胞死亡情况。采用JC-1染色检测GH3细胞的线粒体膜电位（MMP）。检测细胞内ATP水平和细胞内NAD/NADH比值。通过RT-PCR和蛋白质免疫印迹法观察GH3细胞中GPR120的表达情况，并使用小干扰RNA（siRNA）抑制GH3细胞中GPR120的表达。
麦角硫因酸可剂量和时间依赖性地诱导GH3细胞坏死。麦角硫因酸显著降低了GH3细胞的线粒体膜电位（MMP），并降低了细胞内ATP水平。相比之下，麦角硫因酸并未降低分离线粒体的MMP。麦角硫因酸显著提高了细胞内NAD/NADH比值。GH3细胞中表达GPR120，但GPR120激动剂如二十碳五烯酸（EPA）、GW9508和TUG891对GH3细胞的活力没有影响。此外，敲低GPR120的siRNA对麦角硫因酸诱导的GH3细胞死亡没有显著影响。
麦角硫因酸通过降低MMP和抑制ATP生成诱导GH3细胞死亡，这可能是由于通过一种不依赖GPR120的机制抑制了NADH的生成。
