中文摘要 目的： 本研究旨在通过体内外模型探究番茄红素对电离辐射诱导的肠道损伤的预 防及治疗效果的机制。 方法： 将40只无特定病原体级雄性C57BL/6小鼠随机分为对照组（等体积玉米油 灌胃）、模型组（等体积玉米油灌胃，第3天灌胃后给予单次12 Gy X线照射）、 番茄红素对照组（番茄红素灌胃），番茄红素治疗组（番茄红素灌胃，第3天灌 胃后给予单次12 Gy X线照射）。照射后继续相应灌胃7 d。照射后第7天取材。 使用苏木精‐伊红染色、马松染色和天狼星红染色评估肠道损伤与纤维化。免疫 组织化学检测α‐平滑肌肌动蛋白（alpha-smooth muscle actin, α‐SMA）表达。免 疫荧光检测肠道组织中转化生长因子β（transforming growth factor beta, TGF‐β） 和结缔组织生长因子（connective tissue growth factor, CTGF）表达。随后，我们 使用试剂盒检测小鼠血清中丙二醛（malondialdehyde, MDA）、总超氧化物歧化 酶（total superoxide dismutase, T‐SOD）、总抗氧化能力（total antioxidant capacity, T‐AOC）及谷胱甘肽过氧化物酶（glutathione peroxidase, GSH‐PX）活性，以评估 氧化应激水平。实时反转录聚合酶链式反应（RT‐qPCR）检测肠道组织和正常肠 上皮细胞NCM460细胞中肿瘤坏死因子‐α（tumor necrosis factor alpha, TNF‐α）、 白介素‐6（interleukin 6, IL‐6）、白介素‐1β（interleukin 1 beta, IL‐1β）、单核细胞 趋化蛋白-1（monocyte chemoattractant protein 1, MCP-1）、CXC 基序趋化因子配 体-1（c-x-c motif chemokine ligand 1, CXCL-1）、CXC 基序趋化因子配体-2（c-x c motif chemokine ligand 2, CXCL-2）、CXC 基序趋化因子配体-10（c-x-c motif chemokine ligand 10, CXCL-10）和分化簇 68（cluster of differentiation 68, CD68） 的mRNA水平。蛋白质印迹法检测肠道组织中凋亡相关蛋白B细胞淋巴瘤2（b cell lymphoma 2 , Bcl‐2）、BCL2 相关 X 蛋白（bcl-2 associated x protein, Bax）、 裂解型（Cleaved）-胱天蛋白酶3（cysteine containing aspartate specific protease 3, Caspase 3）、裂解型（Cleaved）-聚腺苷二磷酸核糖聚合酶1 （Poly ADP-ribose polymerase-1, PARP-1）表达。在正常肠上皮细胞NCM460细胞中，我们通过CCK8 和克隆形成实验比较了番茄红素对电离辐射细胞毒性的调节。通过实时反转录聚 合酶链式反应（RT‐qPCR），我们检测了细胞中 TNF‐α、IL‐6、IL‐1β、MCP-1、 CXCL-1、CXCL-2、CXCL-10 和 CD68的mRNA水平。蛋白质印迹法检测了Bcl 2、Bax、Cleaved-Caspase‐3、Cleaved-PARP-1 等凋亡相关蛋白的表达。此外，我 VII 北京协和医学院中国医学科学院硕士毕业论文 中文摘要 们进行深度的RNA测序、非靶向代谢组学分析，以揭示番茄红素在缓解放射性 肠道损伤中的潜在分子机制。 结果： 电离辐射暴露诱导小鼠放射性肠道损伤，伴随炎症因子风暴形成和肠上皮细 胞凋亡。与模型组相比，番茄红素治疗组显著改善了辐射引起的肠道损伤指数、 纤维化程度以及纤维化指标TGF‐β及CTGF表达。与此同时，番茄红素通过T AOC、GSH-PX、T-SOD 等抗氧化酶水平，抑制脂质过氧化产物 MDA，从而减 轻机体的氧化应激反应。此外，番茄红素抑制肠道炎症因子TNF-α、IL-6、IL-1β、 MCP-1、CXCL-1、CXCL-2、CXCL-10 和CD68的表达水平，并同时抑制促细胞 凋亡指标Bax、Cleaved-Caspase‐3、Cleaved-PARP-1 的表达，促进抗凋亡指标Bcl 2 的表达。在细胞层面上，番茄红素提高了NCM460细胞的克隆形成能力，同时 抑制了炎症因子表达和促细胞凋亡指标，促进抗凋亡指标表达。在分子机制上， 番茄红素通过抑制促凋亡基因Sept4 和 Gsdme 的表达来减轻细胞凋亡，并通过 促进 Cyp2c70、Cyp2c29 和 Cyp4a10 基因的表达，以及抑制 Pla2g4c、Ptges、 Cyp2j13 和 Alox12b 的表达，调节亚油酸和花生四烯酸代谢通路，抑制炎症和调 节免疫反应，从而缓解放射性肠道损伤。 结论： 番茄红素通过其抗氧化、抗炎和抗凋亡作用，显著缓解电离辐射诱导的肠道 组织损伤，是一种具有潜力的放射性肠道损伤预防和治疗药物。

Abstract Objective: The objective of this study was to investigate the mechanisms underlying the preventive and therapeutic effects of lycopene on ionizing radiation-induced intestinal injury through ex vivo and in vivo models. Methods: Forty pathogen-free male C57BL/6 mice were randomly divided into a control group (equal volume of corn oil by gavage), a model group (equal volume of corn oil by gavage, with a single 12 Gy X-ray irradiation after gavage on day 3), a lycopene control group (lycopene by gavage), and a lycopene treatment group (lycopene by gavage, with a single 12 Gy X-ray irradiation after gavage on day 3). Gavage was continued for 7 d after irradiation, and samples were taken on day 7 after irradiation. Intestinal injury and fibrosis were assessed using hematoxylin-eosin staining, Masson staining and Sirius red staining. Immunohistochemistry was used to detect α-smooth muscle actin (α-SMA) expression. Immunofluorescence was used to detect transforming growth factor beta (TGF-β) and connective tissue growth factor (CTGF) expression in intestinal tissues. Subsequently, we measured malondialdehyde (MDA), total superoxide dismutase (T-SOD), total antioxidant capacity (T-AOC) and glutathione peroxidase (GSH-PX) activities in mouse serum using kits to assess the level of oxidative stress. Real-time reverse transcription polymerase chain reaction (RT qPCR) was used to detect tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), monocyte chemotactic protein 1 (MCP-1), CXC motif chemokine ligand-1 (CXCL-1), CXC motif chemokine ligand 2 (CXCL-2), CXC motif chemokine ligand-10 (CXCL-10) and CD68 mRNA levels. Protein blotting was performed to detect the apoptosis-related proteins B-cell lymphoma 2 (Bcl-2), BCL-2 associated X protein (Bax), cleaved-cysteine containing aspartate specific protease 3 (cleaved-caspase-3), cleaved-Poly ADP-ribose polymerase 1 (Cleaved-PARP-1) expression. In normal intestinal epithelial NCM460 cells, we compared lycopene regulation of ionizing radiation cytotoxicity by CCK8 and clone formation assays. By real-time reverse trascription polymerase chain reaction (RT-qPCR), we examined cellular TNF-α, IL-6, IL-1β, MCP-1, CXCL-1, CXCL-2, CXCL-10 and Cluster of Differentiation 68 (CD68) mRNA levels. The expression of apoptosis-related proteins such as Bcl-2, Bax, Cleaved-Caspase-3 and Cleaved-PARP-1 was detected by protein IX 北京协和医学院中国医学科学院硕士毕业论文 英文摘要 blotting. In addition, we performed in-depth RNA sequencing, and untargeted metabolomics analyses to reveal the potential molecular mechanisms of lycopene in mitigating radioactive intestinal injury. Results: Ionising radiation exposure induced radioactive intestinal injury in mice, accompanied by inflammatory factor storm formation and intestinal epithelial cell apoptosis. Compared with the model group, the lycopene-treated group significantly improved the radiation-induced intestinal injury index, the degree of fibrosis, as well as the expression of TGF-β and CTGF, indicators of fibrosis. Meanwhile, lycopene inhibited the lipid peroxidation product MDA through the level of antioxidant enzymes such as T-AOC, GSH-PX, and T-SOD, thus reducing the oxidative stress of the organism. In addition, lycopene inhibited the expression levels of intestinal inflammatory factors TNF-α, IL-6, IL-1β, MCP-1, CXCL-1, CXCL-2, CXCL-10, and CD68, and simultaneously inhibited the expression of pro-apoptotic indicators Bax, Cleaved Caspase-3, and Cleaved-PARP-1, and promoted the expression of anti-apoptotic indicators Bax, Cleaved-Caspase-3, and Cleaved-PARP-1. expression, and promotes the expression of the anti-apoptotic indicator Bcl-2. At the cellular level, lycopene increased the clone formation ability of NCM460 cells, while inhibiting the expression of inflammatory factors and pro-apoptotic indicators and promoting the expression of anti-apoptotic indicators. In terms of molecular mechanisms, lycopene attenuates apoptosis by inhibiting the expression of pro-apoptotic genes Sept4 and Gsdme, and regulates linoleic acid and arachidonic acid metabolic pathways by promoting the expression of Cyp2c70, Cyp2c29, and Cyp4a10 genes, as well as inhibiting the expression of Pla2g4c, Ptges, Cyp2j13, and Alox12b. Suppresses inflammation and modulates immune responses, thereby alleviating radiological intestinal injury. Conclusion: Lycopene markedly alleviates ionizing radiation–induced injury to intestinal tissue and normal intestinal epithelial cells through its potent antioxidant, anti-inflammatory, and anti-apoptotic properties, highlighting its potential as a promising candidate for the prevention and treatment of radiation-induced intestinal injury.