高硒干扰肝细胞内糖与一碳单位代谢的体外研究  

Study of high selenium interfering with glucose and one-carbon metabolism in hepatocytes in vitro

作　　者：张雪 王建荣 王琴 韩枫 向雪松 刘轶群 黄振武 Zhang Xue;Wang Jianrong;Wang Qin;Han Feng;Xiang Xuesong;Liu Yiqun;Huang Zhenwu(National Institute for Nutrition and Health,Chinese Center for Disease Control and Prevention,Beijing 100050,China;Key Laboratory of Micronutrients Nutrition,National Health Commission,Beijing 100050,China)

机构地区：[1]中国疾病预防控制中心营养与健康所,北京100050 [2]国家卫生健康委微量元素与营养重点实验室,北京100050

出　　处：《卫生研究》2023年第1期115-118,共4页Journal of Hygiene Research

基　　金：国家自然科学基金面上项目(No.81973048)。

摘　　要：目的 探究高硒环境对人正常肝细胞内硒蛋白以及糖代谢和一碳单位代谢相关酶表达的影响。方法 用10个剂量浓度(0、0.001、0.005、0.01、0.05、0.1、0.5、1、5和10μmol/L)的硒代蛋氨酸(SeMet)对人正常肝细胞干预48 h后,采用免疫印迹法检测细胞内硒蛋白P1(SELENOP1)、谷胱甘肽过氧化物酶1(glutathione peroxidase 1,GPX1)、糖酵解旁路关键酶3-磷酸甘油酸脱氢酶(phosphoglycerate dehydrogenase, PHGDH)以及一碳代谢通路关键酶丝氨酸羟甲基转移酶1(serine hydroxymethyltransferase 1,SHMT1)、亚甲基四氢叶酸还原酶(methylenetetrahydrofolate reductase, MTHFR)和蛋氨酸合成酶(methionine synthase, MS)的表达。结果 SeMet在0~10μmol/L范围内,硒蛋白(GPX1和SELENOP1)的表达先升高后降低,GPX1和SELENOP1的拐点分别在0.5和0.1μmol/L;丝氨酸从头合成通路关键酶(PHGDH)和叶酸循环代谢酶(SHMT1、MTHFR和MS)表达与硒蛋白类似,同样先升高后降低,但拐点有差异,分别为0.1μmol/L(PHGDH和SHMT1)和0.01μmol/L(MTHFR和MS)。结论 高硒环境下,细胞内因硒蛋白过表达而导致丝氨酸供应不足,被迫启用糖酵解旁路——丝氨酸从头合成通路合成内源性的丝氨酸,从而引起糖代谢异常。OBJECTIVE To investigate the effects of high selenium environment on the expression of selenoproteins and enzymes related to glucose and one-carbon metabolism in normal human hepatocytes.METHODS Ten different concentrations of selenomethionine(SeMet, 0,0.001, 0.005,0.01, 0.05,0.1, 0.5,1,5 and 10 μmol/L) was added into the normal human hepatocyts and incubated for 48 hours. The expressions of selenoprotein(GPX1 and SELENOP1) and metabolic enzymes(PHGDH, SHMT1, MTHFR and MS) were analyzed by Western blot.RESULTS When the concentration of SeMet was 0-10 μmol/L, the expression trend of selenoprotein(GPX1 and SELENOP1) is similar, which first increases and then decreases. There is a slight difference between the inflection points of GPX1 and SELENOP1, which are respectively 0.5 μmol/L and 0.1 μmol/L. The expression trend of serine de novo synthesis pathway key enzymes(PHGDH) and folate cycle metabolizing enzymes(SHMT1, MTHFR and MS) is similar to that of selenoproteins, which also increases first and then decreases, but the inflection points are different, which are respectively 0.1 μmol/L(PHGDH and SHMT1) and 0.01 μmol/L(MTHFR and MS).CONCLUSION Under the high selenium environment, the glycolytic bypass-serine de novo synthesis pathway is activated to synthesize endogenous serine due to the insufficient intracellular serine supply, causing abnormal glucose metabolism, which is an important extension to the hypothesis of the molecular mechanism of high selenium causing IR.

关 键 词：硒代蛋氨酸 丝氨酸 谷胱甘肽过氧化物酶 硒蛋白P 3-磷酸甘油酸脱氢酶 叶酸循环关键酶 

分 类 号：R151[医药卫生—营养与食品卫生学]