Radiation persistently promoted oxidative stress, activated mTOR via PI3K/Akt, and downregulated autophagy pathway in mouse intestine.
Radiation persistently promoted oxidative stress, activated mTOR via PI3K/Akt, and downregulated autophagy pathway in mouse intestine.
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DOI：
10.1016/j.biocel.2014.10.022
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发表时间：
2014-12
影响因子：
4
通讯作者：
Fornace, Albert J., Jr.
中科院分区：
文献类型：
--
作者：
Datta, Kamal;Suman, Shubhankar;Fornace, Albert J., Jr.
虽然有毒辐射剂量对肠道的急性影响已得到充分证实，但我们尚未在分子水平上获得亚致死辐射引起的慢性肠道扰动的完整谱系。我们研究了放射治疗中常用每日剂量的辐射剂量（2 Gy）对氧化剂和抗氧化剂以及自噬途径的持续影响，这些是影响肠道稳态的相互关联的过程。将 6 至 8 周龄的 C57BL/6J 小鼠 (n=10) 暴露于 2 Gy γ 射线。放射后两个月或十二个月对小鼠实施安乐死，通过手术切除肠道，并使用无菌 PBS 冲洗。将来自空肠-髂骨区域的部分肠固定、冷冻或用于肠上皮细胞（IEC）分离。虽然在分离的 IEC 中评估氧化剂水平和线粒体状态，但使用基于 PCR 的表达阵列和免疫探针在冷冻和固定样品中探测自噬和氧化应激相关信号通路。辐射暴露导致 26 个自噬和 17 个氧化应激相关基因的表达水平发生显着变化。免疫印迹结果显示 Beclin1 和 LC3-II 减少，p62、PI3K/Akt 和 mTOR 增加。流式细胞术数据显示，辐照样品中氧化剂产量增加，线粒体完整性受损。肠道切片的免疫探测显示，照射后 IEC 中 8-oxo-dG 和核 PCNA 增加，自噬体标记物 LC3-II 减少。我们发现亚致死辐射可以持续下调抗氧化剂和自噬信号传导，并上调氧化剂产生和增殖信号传导。辐射诱导的氧化应激促进和自噬下调可能协同作用，改变肠道功能，并对辐射后慢性胃肠道疾病产生影响。
While acute effects of toxic radiation doses on intestine are well established, we are yet to acquire a complete spectrum of sub-lethal radiation-induced chronic intestinal perturbations at the molecular level. We investigated persistent effects of a radiation dose (2 Gy) commonly used as a daily fraction in radiotherapy on oxidants and anti-oxidants, and autophagy pathways, which are interlinked processes affecting intestinal homeostasis. Six to eight weeks old C57BL/6J mice (n=10) were exposed to 2 Gy γ-ray. Mice were euthanized two or twelve months after radiation, intestine surgically removed, and flushed using sterile PBS. Parts of the intestine from jejunal-ilial region were fixed, frozen, or used for intestinal epithelial cell (IEC) isolation. While oxidant levels and mitochondrial status were assessed in isolated IEC, autophagy and oxidative stress related signaling pathways were probed in frozen and fixed samples using PCR-based expression arrays and immunoprobing. Radiation exposure caused significant alterations in the expression level of 26 autophagy and 17 oxidative stress related genes. Immunoblot results showed decreased Beclin1 and LC3-II and increased p62, PI3K/Akt, and mTOR. Flow cytometry data showed increased oxidant production and compromised mitochondrial integrity in irradiated samples. Immunoprobing of intestinal sections showed increased 8-oxo-dG and nuclear PCNA, and decreased autophagosome marker LC3-II in IEC after irradiation. We show that sub-lethal radiation could persistently downregulate anti-oxidants and autophagy signaling, and upregulate oxidant production and proliferative signaling. Radiation-induced promotion of oxidative stress and downregulation of autophagy could work in tandem to alter intestinal functions and have implications for post-radiation chronic gastrointestinal diseases.
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影响因子：
3.7
作者：
Jo YK;Kim SC;Park IJ;Park SJ;Jin DH;Hong SW;Cho DH;Kim JC
通讯作者：
Kim JC
DOI：
10.1042/bj20111451
发表时间：
2012-01-15
期刊：
The Biochemical journal
影响因子：
--
作者：
Lee J;Giordano S;Zhang J
通讯作者：
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影响因子：
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作者：
Li, Shali;Du, Leilei;Yang, SiJun
通讯作者：
Yang, SiJun
影响因子：
11.2
作者：
Apel, Anja;Herr, Ingrid;Mayer, Andreas
通讯作者：
Mayer, Andreas
影响因子：
3.7
作者：
Datta K;Suman S;Kallakury BV;Fornace AJ Jr
通讯作者：
Fornace AJ Jr