Purpose

The thrombopoietin receptor agonist romiplostim (RP) is a therapeutic agent for immune thrombocytopenia that can achieve complete survival in mice exposed to a lethal dose of ionizing radiation. The estimated mechanism of the radio-protective/mitigative effects of RP has been proposed; however, the detailed mechanism of action remains unclear. This study aimed to elucidate the mechanism of the radio-protective/mitigative effects of RP, the fluctuation of protein in the blood was analyzed by proteomics.

Materials and Methods

Eight-week-old female C57BL/6J mice were randomly divided into 5 groups; control at day 0, total-body irradiation (TBI) groups at day 10 and day 18, and TBI plus RP groups at day 10 and day18, consisting of 3 mice per group, and subjected to TBI with 7 Gy of ¹³⁷Cs γ-rays at a dose rate of 0.74 Gy/min. RP was administered intraperitoneally to mice at a dose of 50 µg/kg once daily for 3 days starting 2 hours after TBI. On day 10 and day 18 after TBI, serum collected from each mouse was analyzed by liquid chromatography tandem mass spectrometry.

Results

Nine proteins were identified by proteomics methods from 269 analyzed proteins detected in mice exposed to a lethal dose of TBI: keratin, type II cytoskeletal 1 (KRT1), fructose-1, 6-bisphosphatase (FBP1), cytosolic 10-formyltetrahydrofolate dehydrogenase (ALDH1L1), peptidyl-prolyl cis-trans isomerase A (PPIA), glycine N-methyltransferase (GNMT), glutathione S-transferase Mu 1 (GSTM1), regucalcin (RGN), fructose-bisphosphate aldolase B (ALDOB) and betain–homocysteine S-methyltransferase 1 (BHMT). On the 10th day after TBI, KRT1 was significantly increased (p < 0.05) by 4.26-fold compared to the control group in the TBI group and significantly inhibited in the TBI plus RP group (p < 0.05). Similarly, the expression levels of other 8 proteins detected at 18th day after TBI were significantly increased by 4.29 to 27.44-fold in the TBI group, but significantly decreased in the TBI plus RP group compared to the TBI group, respectively.

Conclusion

Nine proteins were identified by proteomics methods from 269 analyzed proteins detected in mice exposed to a lethal dose of TBI. These proteins are also expected to be indicators of the damage induced by high-dose radiation.

中文翻译：

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放射性致死性血小板生成素受体激动剂romiplostim在暴露于致死性全身照射的小鼠血液中的蛋白质组学变化。

目的

血小板生成素受体激动剂romiplostim（RP）是免疫性血小板减少症的治疗剂，可在暴露于致命剂量的电离辐射的小鼠中完全存活。已经提出了估计的RP的辐射防护/减轻作用的机制。但是，具体的作用机制仍不清楚。这项研究旨在阐明RP的辐射保护/减轻作用的机制，通过蛋白质组学分析了血液中蛋白质的波动。

材料和方法

将八周大的雌性C57BL / 6J小鼠随机分为5组；每组5只。在第0天进行对照组，在第10天和第18天进行全身照射（TBI）组，并在第10天和第18天进行TBI加RP组，每组3只小鼠，并对TBI进行7 Gy的¹³⁷ Csγ-治疗以0.74 Gy / min的剂量率照射。从TBI后2小时开始，每天3次，每天一次以50 µg / kg的剂量腹膜内给予小鼠RP。在TBI后的第10天和第18天，通过液相色谱串联质谱法分析从每只小鼠收集的血清。

结果

通过蛋白质组学方法从暴露于致死剂量的TBI的小鼠中检测到的269种分析蛋白中鉴定出9种蛋白：角蛋白，II型细胞骨架1（KRT1），果糖-1、6-双磷酸酶（FBP1），胞质10-甲酰基四氢叶酸脱氢酶（ALDH1L1 ），肽基脯氨酰顺反异构酶A（PPIA），甘氨酸N-甲基转移酶（GNMT），谷胱甘肽S-转移酶Mu 1（GSTM1），瑞古钙素（RGN），果糖-双磷酸醛缩醛糖酶B（ALDOB）和甜菜碱-半胱氨酸S -甲基转移酶1（BHMT）。在TBI后的第10天 ，与TBI组的对照组相比，KRT1显着增加（p <0.05）4.26倍，而在TBI + RP组中，KRT1明显受到抑制（p <0.05）。同样，与TBI组相比，TBI组在第18天检测到的其他8种蛋白的表达水平分别显着增加了4.29倍至27.44倍，但在TBI + RP组中显着降低。

结论

通过蛋白质组学方法从暴露于致死剂量TBI的小鼠中检测到的269种分析蛋白质中鉴定出9种蛋白质。这些蛋白质也有望成为高剂量辐射诱导的损伤的指标。