Abstract: The proliferation of small intestinal epithelial cells is fundamental to intestinal development and barrier function maintenance in infants and young children. To investigate the effects and mechanisms of ω-3 polyunsaturated fatty acids (docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)), commonly used in infant formula, on this process, this study employed the rat intestinal epithelial cell line 6 (IEC-6) as a model. After DHA and EPA treatment at different combinations of concentration (1, 10, 50, 100 μmol/L) and duration 12, 24, 36, 48 h, cell viability was assessed using the cell counting kit-8 and 5-ethynyl-2’-deoxyuridine assays, and the mRNA and protein expression of key molecules involved in the Wnt/β-catenin signaling pathways were analyzed via real-time quantitative polymerase chain reaction and Western blot. The results showed that both DHA and EPA significantly promoted the proliferation of IEC-6 cells, with optimal concentrations of 100 and 10 μmol/L, respectively, and an optimal treatment duration of 24 h. Specifically, treatment with 100 μmol/L DHA and 10 μmol/L EPA for 24 h increased cell viability by nearly 4- and 3.5-fold compared to the control group (P < 0.001), respectively. Both DHA and EPA activated the Wnt/β-catenin signaling pathway, significantly upregulating the mRNA and protein expression of cell proliferation-related genes such as cyclin D1 and β-catenin (P < 0.05, P < 0.01, or P < 0.001). These findings indicate that DHA and EPA enhance intestinal epithelial cell proliferation by activating the Wnt signaling pathway.

Key words: ω-3 polyunsaturated fatty acids; docosahexaenoic acid; eicosapentaenoic acid; intestinal epithelial cells; cell proliferation

摘要： 小肠上皮细胞增殖是婴幼儿肠道发育与屏障功能维持的生理基础。为探究婴幼儿配方乳粉中常见的二十二碳六烯酸（docosahexaenoic acid，DHA）和二十碳五烯酸（eicosapentaenoic acid，EPA）对肠上皮细胞增殖的影响及其分子机制，采用大鼠小肠上皮细胞系6（intestinal epithelial cell line 6，IEC-6）模型，采用CCK-8和5-乙炔基-2’-脱氧尿苷法检测不同浓度（1、10、50、100 μmol/L）DHA和EPA处理不同时间（12、24、36、48 h）后的细胞活力，并利用实时荧光定量聚合酶链式反应和蛋白质印迹分析Wnt/β-catenin信号通路关键分子相对表达水平。结果表明，DHA与EPA均可有效促进IEC-6细胞增殖，最适浓度分别为100 μmol/L和10 μmol/L，最佳处理时间为24 h。其中，100 μmol/L DHA处理24 h后，细胞活力较对照组高度显著提升将近4 倍（P＜0.001），10 μmol/L EPA处理24 h后，细胞活力较对照组高度显著提升3.5 倍（P＜0.001）。两者均能够通过激活Wnt/β-catenin信号通路显著上调cyclin D1、β-catenin等增殖相关基因和蛋白相对表达水平（P＜0.05、P＜0.01、P＜0.001）。综上，DHA和EPA可通过激活Wnt/β-catenin信号通路促进肠上皮细胞增殖。

关键词: ω-3多不饱和脂肪酸；二十二碳六烯酸；二十碳五烯酸；小肠上皮细胞；细胞增殖