Saito Yoshiro, Takahashi Kazuhiko
Department of Hygienic Chemistry, Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
Eur J Biochem. 2002 Nov;269(22):5746-51. doi: 10.1046/j.1432-1033.2002.03298.x.
Selenium (Se) is well known to be essential for cell culture when using a serum-free medium, but not when a medium containing serum is used. This finding suggests that serum contains some usable form of Se. To identify the Se-supplier, T-lymphoma (Jurkat) cells were cultured for 3 days in the presence of human serum immunodepleted of Se-containing serum protein, selenoprotein P or extracellular glutathione peroxidase. The Se-dependent enzyme activities (glutathione peroxidases and thioredoxin reductase) and Se content within the cells markedly decreased only when cultured with selenoprotein P-depleted serum. Compared with other Se-containing proteins, the addition of purified selenoprotein P to the selenoprotein P-depleted serum or a serum-free medium was the most effective for the recovery of cellular glutathione peroxidase activity (index of Se status). These results suggest that selenoprotein P functions as a Se-supply protein, delivering Se to the cells.
众所周知，在使用无血清培养基时，硒（Se）对细胞培养至关重要，但在使用含血清的培养基时则不然。这一发现表明血清中含有某种可利用形式的硒。为了确定硒的供应源，将T淋巴瘤（Jurkat）细胞在不含含硒血清蛋白、硒蛋白P或细胞外谷胱甘肽过氧化物酶的人血清存在下培养3天。仅在用缺乏硒蛋白P的血清培养时，细胞内的硒依赖性酶活性（谷胱甘肽过氧化物酶和硫氧还蛋白还原酶）和硒含量才会显著降低。与其他含硒蛋白相比，向缺乏硒蛋白P的血清或无血清培养基中添加纯化的硒蛋白P对恢复细胞谷胱甘肽过氧化物酶活性（硒状态指标）最为有效。这些结果表明，硒蛋白P作为一种硒供应蛋白，将硒传递给细胞。
