Lipocalin-type prostaglandin D synthase protects against oxidative stress-induced neuronal cell death
Lipocalin-type prostaglandin D synthase protects against oxidative stress-induced neuronal cell death
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DOI：
10.1042/bj20111889
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发表时间：
2012-04-01
影响因子：
4.1
通讯作者：
Inui, Takashi
中科院分区：
文献类型：
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作者：
Fukuhara, Ayano;Yamada, Mao;Inui, Takashi
L-PGDS [lipocalin-type POD（prostaglandin D）synthase]是一种双功能蛋白，作为PGD（2）产生酶和脂质转运蛋白。L-PGDS是脂质运载蛋白超家族的成员，可以结合多种亲脂性分子。在本研究中，我们证明了L-PGDS对H2 O2诱导的神经母细胞瘤细胞株SH-SY 5 Y凋亡的保护作用。H2 O2处理的神经细胞中L-PODS表达增加，L-PGDS水平与H2 O2诱导的细胞凋亡高度相关，表明L-PGDS保护神经细胞免受H2 O2介导的细胞死亡。细胞活力测定显示，L-PGDS以浓度依赖性方式保护H2 O2诱导的细胞死亡。此外，H_2O_2处理的L-PGDS中游离巯基的滴定表明，H_2O_2与L-PGDS的Cys（65）的巯基反应。H2 O2处理的L-PGDS的MALDI-TOF（基质辅助激光解吸电离飞行时间）-MS光谱显示，相对于未处理的蛋白质，质量增加了32 Da，表明巯基被氧化为亚磺酸。氧化的L-PODS与亲脂性分子的结合亲和力与未处理的L-PGDS相当。综上所述，这些结果表明，L-PGDS通过清除活性氧而不失去其配体结合功能来保护神经元细胞免于死亡。L-PGDS的新功能可用于抑制氧化应激介导的神经退行性疾病。
L-PGDS [lipocalin-type POD (prostaglandin D) synthase] is a dual-functional protein, acting as a PGD(2)-producing enzyme and a lipid transporter. L-PGDS is a member of the lipocalin superfamily and can bind a wide variety of lipophilic molecules. In the present study we demonstrate the protective effect of L-PGDS on H2O2-induced apoptosis in neuroblastoma cell line SH-SY5Y. L-PODS expression was increased in H2O2-treated neuronal cells, and the L-PGDS level was highly associated with H2O2-induced apoptosis, indicating that L-PGDS protected the neuronal cells against H2O2-mediated cell death. A cell viability assay revealed that L-PGDS protected against H2O2-induced cell death in a concentration-dependent manner. Furthermore, the titration of free thiols in H2O2-treated L-PGDS revealed that H2O2 reacted with the thiol of Cys(65) of L-PGDS. The MALDI-TOF (matrix-assisted laser-desorption ionization-time-of-flight)-MS spectrum of H2O2-treated L-PGDS showed a 32 Da increase in the mass relative to that of the untreated protein, showing that the thiol was oxidized to sulfinic acid. The binding affinities of oxidized L-PODS for lipophilic molecules were comparable with those of untreated L-PGDS. Taken together, these results demonstrate that L-PGDS protected against neuronal cell death by scavenging reactive oxygen species without losing its ligand-binding function. The novel function of L-PGDS could be useful for the suppression of oxidative stress-mediated neurodegenerative diseases.