Institute of Radiation Biology, Helmholtz Zentrum München GmbH, German Research Center for Environmental Health GmbH (HMGU), Ingolstaedter Landstraße 1, 85764, Neuherberg, Germany.
Research Unit Protein Science, Helmholtz Zentrum München GmbH, German Research Center for Environmental Health GmbH (HMGU), 80939, Munich, Germany.
Radiat Environ Biophys. 2021 Aug;60(3):397-410. doi: 10.1007/s00411-021-00925-7. Epub 2021 Jul 21.
Reliable data on the effects of chronic prenatal exposure to low dose (LD) of ionizing radiation in humans are missing. There are concerns about adverse long-term effects that may persist throughout postnatal life of the offspring. Due to their slow cell cycle kinetics and life-long residence time in the organism, mesenchymal stem cells (MSCs) are more susceptible to low level genotoxic stress caused by extrinsic multiple LD events. The aim of this study was to investigate the effect of chronic, prenatal LD gamma irradiation to the biology of MSCs later in life. C3H mice were exposed in utero to chronic prenatal irradiation of 10 mGy/day over a period of 3 weeks. Two years later, MSCs were isolated from the bone marrow and analyzed in vitro for their radiosensitivity, for cellular senescence and for DNA double-strand break recognition after a second acute gamma-irradiation. In addition to these cellular assays, changes in protein expression were measured using HPLC-MS/MS and dysregulated molecular signaling pathways identified using bioinformatics. We observed radiation-induced proteomic changes in MSCs from the offspring of in utero irradiated mice (leading to ~ 9.4% of all detected proteins being either up- or downregulated) as compared to non-irradiated controls. The proteomic changes map to regulation pathways involved in the extracellular matrix, the response to oxidative stress, and the Wnt signaling pathway. In addition, chronic prenatal LD irradiation lead to an increased rate of in vitro radiation-induced senescence later in life and to an increased number of residual DNA double-strand breaks after 4 Gy irradiation, indicating a remarkable interaction of in vivo radiation in combination with a second acute dose of in vitro radiation. This study provides the first insight into a molecular mechanism of persistent MSC damage response by ionizing radiation exposure during prenatal time and will help to predict therapeutic safety and efficacy with respect to a clinical application of stem cells.
关于人类慢性产前低剂量（LD）电离辐射暴露的影响，目前尚无可靠的数据。人们担心可能会对后代的出生后生活产生长期的不良影响。由于间充质干细胞（MSCs）的细胞周期动力学较慢，并且在生物体中的寿命较长，因此它们更容易受到外源性多次 LD 事件引起的低水平遗传毒性应激的影响。本研究旨在探讨慢性产前 LDγ辐射对 MSCS 后期生物学的影响。C3H 小鼠在子宫内接受为期 3 周、每天 10mGy 的慢性产前照射。2 年后，从骨髓中分离出 MSCS，并在体外分析其放射敏感性、细胞衰老以及第二次急性γ照射后的 DNA 双链断裂识别。除了这些细胞检测外，还使用 HPLC-MS/MS 测量蛋白质表达的变化，并使用生物信息学鉴定失调的分子信号通路。与未照射的对照组相比，我们观察到来自宫内照射小鼠后代的 MSC 中存在辐射诱导的蛋白质组变化（导致~9.4%的所有检测到的蛋白质上调或下调）。蛋白质组变化映射到参与细胞外基质、氧化应激反应和 Wnt 信号通路的调节途径。此外，慢性产前 LD 照射导致晚年体外辐射诱导衰老的速度增加，并且在 4Gy 照射后残留的 DNA 双链断裂数量增加，这表明体内辐射与第二次体外急性剂量相结合的显著相互作用。这项研究首次深入了解了在产前时期电离辐射暴露对 MSC 持续损伤反应的分子机制，并将有助于预测干细胞临床应用的治疗安全性和疗效。
