一种基于氨基酸的口服补液溶液可调节小鼠的辐射诱导的肠道屏障破坏。
An Amino Acid-Based Oral Rehydration Solution Regulates Radiation-Induced Intestinal Barrier Disruption in Mice.
机构信息
Entrinsic Health Solutions, Norwood, MA, USA.
Department of Radiation Oncology, University of Florida Shands Cancer Center, Gainesville, FL, USA.
出版信息
J Nutr. 2020 May 1;150(5):1100-1108. doi: 10.1093/jn/nxaa025.
BACKGROUND
Radiotherapy inadvertently affects gastrointestinal (GI) epithelial cells, causing intestinal barrier disruption and increased permeability.
OBJECTIVE
We examined the effect of amino acid-based oral rehydration solution (AA-ORS) on radiation-induced changes of intestinal barrier function and epithelial tight junctions (TJs) in a randomized experimental study using a total-body irradiation (TBI) mouse model.
METHODS
Eight-week-old male Swiss mice received a single-dose TBI (0, 1, 3, or 5 Gy), and subsequent gastric gavage with AA-ORS (threonine, valine, serine, tyrosine, and aspartic acid) or saline for 2 or 6 d. Intestinal barrier function of mouse ileum was characterized by electrophysiological analysis of conductance, anion selectivity, and paracellular permeability [fluorescein isothiocyanate (FITC)-dextran]. Ultrastructural changes of TJs were evaluated by transmission electron microscopy. Membrane protein and mRNA expression of claudin-1, -2, -3, -5, and -7, occludin, and E-cadherin were analyzed with western blot, qPCR, and immunohistochemistry. Nonparametric tests were used to compare treatment-dose differences for each time point.
RESULTS
Saline-treated mice had a higher conductance at doses as low as 3 Gy, and as early as 2 d post-TBI compared with 0 Gy (P < 0.001). Paracellular permeability and dilution potential were increased 6 d after 5 Gy TBI (P < 0.001). Conductance decreased with AA-ORS after 2 d in 3-Gy and 5-Gy mice (P < 0.05 and P < 0.001), and on day 6 after 5 Gy TBI (P < 0.001). Anion selectivity and FITC permeability decreased from 0.73 ± 0.02 to 0.61 ± 0.03 pCl/pNa (P < 0.01) and from 2.7 ± 0.1 × 105 to 2.1 ± 0.1 × 105 RFU (P < 0.001) in 5-Gy mice treated with AA-ORS for 6 d compared with saline. Irradiation-induced ultrastructural changes of TJs characterized by decreased electron density and gap formation improved with AA-ORS. Reduced claudin-1, -3, and -7 membrane expression after TBI recovered with AA-ORS within 6 d, whereas claudin-2 decreased indicating restitution of TJ proteins.
CONCLUSIONS
Radiation-induced functional and structural disruption of the intestinal barrier in mice is reversed by AA-ORS rendering AA-ORS a potential treatment option in prospective clinical trials in patients with gastrointestinal barrier dysfunction.
背景
放射治疗会无意中影响胃肠道（GI）上皮细胞，导致肠道屏障破坏和通透性增加。
目的
我们通过全身照射（TBI）小鼠模型的随机实验研究，研究氨基酸口服补液溶液（AA-ORS）对辐射诱导的肠道屏障功能和上皮紧密连接（TJ）变化的影响。
方法
8 周龄雄性瑞士小鼠接受单次 TBI（0、1、3 或 5 Gy），随后用 AA-ORS（苏氨酸、缬氨酸、丝氨酸、酪氨酸和天冬氨酸）或生理盐水进行胃灌胃 2 或 6 d。通过电生理学分析电导、阴离子选择性和细胞旁通透性[荧光素异硫氰酸酯（FITC）-葡聚糖]来描述小鼠回肠的肠道屏障功能。通过透射电子显微镜评估 TJ 的超微结构变化。用 Western blot、qPCR 和免疫组织化学分析紧密连接蛋白 1、-2、-3、-5、-7、occludin 和 E-cadherin 的膜蛋白和 mRNA 表达。使用非参数检验比较每个时间点的治疗剂量差异。
结果
与 0 Gy 相比，生理盐水处理的小鼠在低至 3 Gy 时的电导率更高，在 TBI 后 2 天即可检测到（P < 0.001）。5 Gy TBI 后 6 天，细胞旁通透性和稀释电位增加（P < 0.001）。2 Gy 和 5 Gy 小鼠用 AA-ORS 治疗 2 天后，电导率降低（P < 0.05 和 P < 0.001），5 Gy TBI 后 6 天降低（P < 0.001）。阴离子选择性和 FITC 通透性从 0.73±0.02 降低至 0.61±0.03 pCl/pNa（P < 0.01），从 2.7±0.1×105 降低至 2.1±0.1×105 RFU（P < 0.001）在接受 AA-ORS 治疗 6 天的 5 Gy 小鼠中。用 AA-ORS 治疗可改善 TJ 超微结构的辐射诱导变化，表现为电子密度降低和间隙形成。TBI 后紧密连接蛋白 1、-3 和 -7 的膜表达减少，用 AA-ORS 治疗 6 天可恢复，而紧密连接蛋白 2 减少表明 TJ 蛋白的修复。
结论
AA-ORS 逆转了小鼠肠道屏障的功能和结构损伤，使 AA-ORS 成为胃肠道屏障功能障碍患者前瞻性临床试验中的一种潜在治疗选择。
Zotero 插件