Department of Safety, Health and Environmental Engineering, Ming Chi University of Technology, New Taipei City, 24301, Taiwan.
Chronic Diseases and Health Promotion Research Center, Chang Gung University of Science and Technology, Chiayi, 61363, Taiwan.
J Food Drug Anal. 2021 Sep 15;29(3):402-418. doi: 10.38212/2224-6614.3369.
Lactoferrin (LF) is secreted by mammals and displays extensive biological effects. We previously reported that bovine LF (BLF) can boost the cold tolerance of a well-applied probiotic strain, Lactobacillus rhamnosus GG (LGG), to grow robustly under a cold environment, but the molecular mechanism is not clear. Here, RNA-seq analysis was conducted to ascertain molecular pathways underlying cold tolerance exerted by BLF. LGG was cultured in a cold environment (22 °C) in the presence or absence of BLF. Transcriptome analysis indicated that BLF significantly elicited 1.2-3.2 fold (log2 Fold change) higher expression levels of genes related to stress, defense, cell division, and transporter in LGG, including the genes CspA, LytR, XRE, MerR, and GpsB. The KEGG pathway and GO analyses confirmed that BLF can modulate a few central pathways to boost the growth of LGG. BLF also reduced metabolic pathways involved in purine, amino acid, pyrimidine, one-carbon metabolism, and secondary metabolites in LGG. We speculate that the reduction of the above pathways may play key roles to reduce energy requirement and maintain carbon metabolism balance in LGG for surviving and growing in a cold state, and BLF can be an excellent prebiotic to LGG cultured in this cold condition (22 °C). Overall, this study uncovers the molecular effects of BLF on LGG.
乳铁蛋白（LF）是哺乳动物分泌的一种蛋白，具有广泛的生物学效应。我们之前的研究表明，牛乳铁蛋白（BLF）可以增强一种应用广泛的益生菌——鼠李糖乳杆菌 GG（LGG）的耐寒性，使其在寒冷环境下能够健壮生长，但具体的分子机制尚不清楚。在此，我们进行了 RNA-seq 分析，以确定 BLF 增强耐寒性的分子途径。在存在或不存在 BLF 的情况下，将 LGG 在寒冷环境（22°C）中培养。转录组分析表明，BLF 显著诱导了与应激、防御、细胞分裂和转运体相关的基因表达水平提高了 1.2-3.2 倍（log2 Fold change），包括 CspA、LytR、XRE、MerR 和 GpsB 等基因。KEGG 通路和 GO 分析证实，BLF 可以调节几个核心通路来促进 LGG 的生长。BLF 还降低了 LGG 中涉及嘌呤、氨基酸、嘧啶、一碳代谢和次生代谢物的代谢途径。我们推测，上述途径的减少可能在降低能量需求和维持 LGG 在寒冷状态下的碳代谢平衡方面发挥关键作用，并且 BLF 可以作为 LGG 在这种寒冷条件（22°C）下培养的优秀益生元。总之，本研究揭示了 BLF 对 LGG 的分子影响。
