1 Department of Anatomy and Neuroscience, University College Cork, Western Gateway Building, Western Rd., Cork, Ireland.
2 APC Microbiome Institute, University College Cork, Cork, Ireland.
Benef Microbes. 2018 Feb 27;9(2):175-183. doi: 10.3920/BM2017.0013. Epub 2017 Dec 21.
The enteric microbiota is characterised by a balance and composition that is unique to the host. It is important to understand the mechanisms through which the host can maintain the composition of the gut microbiota. MicroRNAs (miRNA) are implicated in intercellular communication and have been isolated from bodily fluids including stool. Recent findings suggest that miRNA produced by the host's intestinal epithelial cells (IECs) participate in shaping the microbiota. To investigate whether miRNA expression was influenced by the gut microbiota we measured the expression of miRNAs expressed by intestinal epithelial cells in faeces. Specifically, we measured miRNA expression in faeces from germ-free (GF) and conventional mice and similarly in a rat model of antibiotic-mediated depletion of the gut microbiota control rats. In adult male GF and conventional mice and adult Sprague Dawley (SD) rats were treated with a combination of antibiotics for 8 weeks; total RNA was extracted from faecal pellets taken at week 0, 2, 4, 6 week 8 and the expression of let-7b-3p, miR-141-3p, miR-200a-3p and miR-1224-5p (miRNAs known to be expressed in IECs) were measured relative to U6 at each time point using qRT-PCR. In GF animals the expression of let-7b, miR-141 and miR-200a in faeces was lower compared to conventional mice. Following antibiotic-mediated depletion of gut microbiota, rats showed two divergent profiles of miRNA expression. Following two weeks of antibiotic treatment, the expression of let-7b and miR-1224 dropped significantly and remained low for the remainder of the study. The expression of miR-200a and miR-141 was significantly higher at week 2 than before antibiotic treatment commenced. Subsequently, the expression of miR-200a and miR-141 decreased at week 4 and continued to decrease at week 6. This data demonstrates that miRNAs can be used as an independent, non-invasive marker of microbial fluctuations along with gut pathology in the intestine.
肠内微生物群的特征是具有宿主特有的平衡和组成。了解宿主维持肠道微生物群组成的机制非常重要。microRNAs (miRNA) 参与细胞间通讯，并已从包括粪便在内的体液中分离出来。最近的研究结果表明，宿主肠道上皮细胞 (IEC) 产生的 miRNA 参与了微生物群的形成。为了研究 miRNA 的表达是否受肠道微生物群的影响，我们测量了粪便中肠道上皮细胞表达的 miRNA 的表达。具体来说，我们测量了无菌 (GF) 和常规小鼠以及抗生素介导的肠道微生物群消耗的大鼠模型中的 miRNA 表达。在成年雄性 GF 和常规小鼠和成年 Sprague Dawley (SD) 大鼠中，用抗生素混合物治疗 8 周；从第 0、2、4、6 和 8 周的粪便中提取总 RNA，并使用 qRT-PCR 测量 let-7b-3p、miR-141-3p、miR-200a-3p 和 miR-1224-5p（已知在 IEC 中表达的 miRNA）的表达，相对于 U6 在每个时间点。在 GF 动物中，粪便中 let-7b、miR-141 和 miR-200a 的表达低于常规小鼠。在抗生素介导的肠道微生物群消耗后，大鼠表现出两种不同的 miRNA 表达谱。在两周的抗生素治疗后，let-7b 和 miR-1224 的表达显著下降，并在研究的其余时间保持低水平。miR-200a 和 miR-141 的表达在第 2 周比抗生素治疗开始前显著升高。随后，miR-200a 和 miR-141 的表达在第 4 周下降，并在第 6 周继续下降。这项数据表明，miRNA 可以作为一种独立的、非侵入性的微生物波动标志物，与肠道中的肠道病理学一起使用。
