Table 4_Dietary supplementation of nucleotides and oligosaccharides in kittens reduces the expression of circulating miR-1-3p, miR-133a-3p, miR-206-3p and miR-383-5p.docx

The immune system of kittens is less efficient at fighting pathogens compared to adult cats with kittens being more susceptible to infections. Increasing evidence shows that dietary interventions can enhance immunity in mammals and modulate the expression of microRNAs (miRNAs) with key immune functions, however research in kittens is limited. Diets that can enhance the ability of a kitten's developing immune system to successfully fight infections, and where effects can be monitored by veterinarians, are highly sought-after. Here, we utilised small RNA sequencing (RNA-Seq) to investigate the effects of an experimental (test) diet containing nucleotides and oligosaccharides on the global expression of circulating miRNAs in 23-week-old kittens (n = 9). Furthermore, we determined whether these effects were sustained up to 10 weeks post-supplementation. Kittens fed with the test diet were found to have a lower expression of a specific subset of circulating miRNAs, namely miR-1-3p, miR-133a-3p, miR-206-3p and miR-383-5p, compared to animals fed with a control diet. Notably, this effect persisted 10 weeks post-supplementation. Bioinformatics analysis indicated that these miRNAs target immune-related genes and pathways. As such, they may hold potential as biomarkers to monitor immune performance of kittens and inform the prescription of veterinary diets.

与成年猫相比，幼猫的免疫系统对抗病原体的效率更低，且更易发生感染。越来越多的证据表明，饮食干预可增强哺乳动物的免疫力，并调控具有关键免疫功能的微小RNA（microRNAs，miRNAs）的表达，但针对幼猫的相关研究仍较为匮乏。目前，学界亟需能够增强幼猫发育中免疫系统对抗感染能力的日粮，且该日粮的干预效果可由兽医进行监测。本研究采用小RNA测序（small RNA sequencing，RNA-Seq）技术，探究了添加核苷酸与寡糖的实验（受试）日粮对23周龄幼猫（n=9）循环微小RNA整体表达谱的影响。此外，本研究还考察了该效应在日粮补充后是否可维持长达10周。研究结果显示，与饲喂对照日粮的幼猫相比，饲喂受试日粮的幼猫体内特定循环微小RNA亚群的表达水平显著降低，具体包括miR-1-3p、miR-133a-3p、miR-206-3p及miR-383-5p。值得注意的是，该调控效应在日粮补充结束10周后仍持续存在。生物信息学分析表明，上述这些微小RNA的靶基因均为免疫相关基因，且参与免疫相关通路。综上，这些微小RNA或可作为监测幼猫免疫功能的生物标志物，为兽医日粮处方的制定提供参考依据。