吡格列酮对KKAy小鼠肠道菌群的影响

The Influence of Pioglitazone on the Gut Microbes in KKAy Mice

目的研究2型糖尿病动物模型KKAy小鼠与正常C57BL/6J小鼠肠道微生物的差异和降糖药物吡格列酮对KKAy小鼠肠道菌群结构的影响,阐明宿主基因型对肠道菌群的影响及吡格列酮、肠道菌群和2型糖尿病之间的内在联系,为研究和治疗2型糖尿病提供新思路。方法将KKAy小鼠分为药物组和模型对照组,C57BL/6J小鼠为正常对照组,定期收集小鼠粪便样品,提取其中微生物的总DNA,PCR扩增16S rDNA V3区,用DGGE(变性梯度凝胶电泳)技术分离扩增片段,结合DGGE图谱的数字化分析和特异条带克隆测序等分子生物学方法分析肠道微生物群落结构。结果 KKAy小鼠与C57BL/6J小鼠的DGGE图谱有明显差异,正常对照组小鼠肠道菌群多样性保持稳定,而模型对照组和药物组肠道菌群的多样性随时间延长逐渐下降,药物组下降趋势略大于模型对照组。主成分分析结果显示,喂药前KKAy小鼠(包括模型对照组和药物组)和C57BL/6J小鼠沿PC1方向分别聚为2类,随着实验的延续,药物组逐渐靠近正常对照组,并且喂药70 d后沿PC1方向,药物组与正常对照组聚在一起,而模型对照组另聚一类。结论肠道微生物群落结构与宿主的基因型有明显的相关性;吡格列酮抑制某些细菌生长,降低了肠道菌群的多样性,同时能够改善肠道中主要微生物的菌群结构。

Objective To research the difference between the gut microbes in type 2 diabetes animal model KKAy mice and those in normal C57BL/6J mice and the influence of hypoglycemic drug pioglitazone on the gut microbes in KKAy mice, in order to elucidate the influence of host genotypes on the gut microbes and the interrelationship among pioglitazone, gut microbes and type 2 diabetes and provide new ideas for research and treatment of type 2 diabetes. Methods The KKAy mice were divided into drug group and model control group, with the C57BL/6J mice as normal control. The mice faecal samples were collected and total DNA of microbes in feces was extracted. 16S rDNA V3 region was amplified by PCR and amplified fragments were separated by DGGE （denaturing gradient gel electrophoresis）. Digital analyzing of DGGE profiles and clone and sequencing of specific bands were combined to analyze gut microbial community structure. Results The difference between DGGE profiles of KKAy mice and those of C57BL/6J mice was obvious. The microbial diversity of normal control group remained stable, but that of model control group and drug group gradually declined and more decrease happened in the drug group than in model control group. PCA of DGGE profiles results showed that C57BL/6J mice and KKAy mice （model control group and drug group） separated in two parts along the PC1 axis before drug treatment. As the experiment went on, the drug group gradually moved close to the normal control group. And 70 days after drug treatment, along the PC 1 axis, two groups merged, while model control group moved away and separated itself. Conclusion There was an obvious correlation between gut microbial community structure and host genotypes. Pioglitazone inhibited bacterial growth and reduced the diversity of gut microbes, simultaneously improved microbial structure in gut.