Guo Shuangshuang, Guo Yuming, Ergun Ayla, Lu Lei, Walker W Allan, Ganguli Kriston
State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China; Mucosal Immunology and Biology Research Center, Massachusetts General Hospital for Children and Harvard Medical School, Charlestown, Massachusetts, United States of America.
State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China.
PLoS One. 2015 Apr 23;10(4):e0124549. doi: 10.1371/journal.pone.0124549. eCollection 2015.
Combination regimens of Bifidobacterium infantis and Lactobacillus acidophilus have been demonstrated to prevent necrotizing enterocolitis (NEC) in clinical trials. However, the molecular mechanisms responsible for this protective effect are not well understood. Additionally, conditioned media from individual cultures of these two probiotics show strain specific modulation of inflammation using in vitro human intestinal NEC models. Here we report a transcription profiling analysis of gene expression in immature human fetal intestinal epithelial cells (H4 cells) pretreated with conditioned media from B. infantis (BCM) or L. acidophilus (LCM) prior to IL-1β stimulation. Compared with control media, the two probiotic-conditioned media (PCM) treatments altered the expression of hundreds of genes involved in the immune response, apoptosis and cell survival, cell adhesion, the cell cycle, development and angiogenesis. In IL-1β-stimulated cells, PCM treatment decreased the upregulation of genes in the NF-κB activation pathway and downregulated genes associated with extracellular matrix (ECM) remodeling. Compared with LCM, BCM showed more significant modulatory effects on ECM remodeling, reflected by a lower p value. IL-6 and IL-8 production was significantly reduced in IL-1β-stimulated cells pretreated with PCM (p<0.05), which was consistent with their altered gene expression. Western blot analysis showed that compared with IL-1β stimulation alone, PCM treatment attenuated the decrease of cytoplasmic IκBα and NF-κB p65 levels as well as the increase of nuclear NF-κB p65 levels in the stimulated cells (p<0.05). In conclusion, PCM treatment exerted anti-inflammatory effects in immature human fetal enterocytes primarily by modulating genes in the NF-κB signaling and ECM remodeling pathways. Additionally, some components of these signaling pathways, particularly the ECM remodeling pathway, were more profoundly affected by BCM than LCM.
临床试验已证明，婴儿双歧杆菌和嗜酸乳杆菌的联合疗法可预防坏死性小肠结肠炎（NEC）。然而，这种保护作用的分子机制尚不清楚。此外，使用体外人肠道NEC模型，这两种益生菌的单独培养条件培养基显示出对炎症的菌株特异性调节作用。在此，我们报告了在白细胞介素-1β（IL-1β）刺激之前，用婴儿双歧杆菌条件培养基（BCM）或嗜酸乳杆菌条件培养基（LCM）预处理的未成熟人胎儿肠上皮细胞（H4细胞）中基因表达的转录谱分析。与对照培养基相比，两种益生菌条件培养基（PCM）处理改变了数百个参与免疫反应、细胞凋亡和细胞存活、细胞粘附、细胞周期、发育和血管生成的基因的表达。在IL-1β刺激的细胞中，PCM处理降低了NF-κB激活途径中基因的上调，并下调了与细胞外基质（ECM）重塑相关的基因。与LCM相比，BCM对ECM重塑的调节作用更显著，p值更低即体现了这一点。在用PCM预处理的IL-1β刺激细胞中，白细胞介素-6（IL-6）和白细胞介素-8（IL-8）的产生显著减少（p<0.05），这与其基因表达的改变一致。蛋白质免疫印迹分析表明，与单独的IL-1β刺激相比，PCM处理减弱了刺激细胞中细胞质IκBα和NF-κB p65水平的降低以及细胞核NF-κB p65水平的升高（p<0.05）。总之，PCM处理主要通过调节NF-κB信号和ECM重塑途径中的基因，在未成熟人胎儿肠上皮细胞中发挥抗炎作用。此外，这些信号通路的一些成分，特别是ECM重塑途径，受BCM的影响比LCM更深远。
