Objective: To investigate the effect of irradiated human lung fibroblasts (HLFs) on the canonical Wnt/β-catenin signaling pathway in human umbilical cord mesenchymal stem cells (HUMSCs).
Methods: HUMSCs were cultured alone (single group) or co-cultured with HLFs exposed to 5Gy X-rays (co-culture group). The protein levels of GSK-3β, p-GSK-3β, FRAT1 and β-catenin in HUMSCs were examined by Western blotting 3 days after culture or co-culture. WISP-1 protein levels in conditioned medium were examined by ELISA.
Results: The levels of p-GSK3β/GSK3β (0.15 ± 0.05), FRAT1 (0.48 ± 0.07) and β-catenin (0.50 ± 0.07) in co-cultured HUMSCs significantly decreased compared to those in single group (0.55 ± 0.05, 1.16 ± 0.13 and 2.39 ± 0.15, all P<0.05). The supernatant level of WISP-1 in co-culture group was significantly decreased [(602.23 ± 161.47) ng/mL], compared to the single group [(977.77 ± 110.56) ng/mL, P<0.05].
Conclusion: Irradiated HLFs attenuate the activation of canonical Wnt/β-catenin signaling pathway in HUMSCs in vitro.
目的: 体外研究放射线照射后的人肺成纤维细胞（HLFs）对人脐带间充质干细胞（HUMSCs）中经典Wnt/β-catenin信号通路的影响。
方法: 实验细胞分为共培养组和单纯HUMSCs组，共培养组为5Gy X射线照射后的HLFs通过Transwell系统与HUMSCs共培养。细胞培养3d后，蛋白质印迹法检测HUMSCs中GSK-3β、p-GSK-3β、FRAT1和胞核内β-catenin蛋白表达，酶联免疫吸附试验检测细胞培养上清液中WISP-1蛋白表达。
结果: 共培养组HUMSCs中p-GSK-3β/GSK-3β相对比值（0.15±0.05）和FRAT1表达水平（0.48±0.07）较单纯HUMSCs组（0.55±0.05和1.16±0.13）明显下降，共培养组HUMSCs胞核内β-catenin（0.50±0.07）也较单纯HUMSCs组（2.39±0.15）明显下降；共培养组HUMSCs培养上清液中WISP-1蛋白表达[（602.23±161.47）ng/mL]较单纯HUMSCs组[（977.77±110.56）ng/mL]明显下降，差异均有统计学意义（均 P＜0.05）。
结论: 放射线照射后的HLFs对HUMSCs中经典Wnt/β-catenin通路具有抑制作用。