Potential Effect Of Human Milk Exosomal MiRNAs On The Occurrence Of Neonatal Breast Milk Jaundice

Objective: To demonstrate the association of exosomal miRNAs in human milk and the occurrence of neonate breast milk jaundice(BMJ);to analyze the effect of oleic acid,linoleic acid and DHA in human milk on neonatal BMJ.And the possible related mechanism is discussed in this paper.Methods: The research has recruited 12 mother-infant dyads from Shanghai Children’s Medical Center of Shanghai Jiao Tong University School of Medicine and UIB International Maternity Care Center during September 2016 to December 2016,which were divided into two groups(the BMJ group and control group).We firstly identified the exosome prepartation extracted from human milk by four methods of transmission electron microscopy(TEM),nanoparticle tracking analyzer(NTA),flow cytometry(FCM),and Western blotting in this study.Then,we detected the expression profile of miRNA in human milk exosomes by small RNA sequencing.According to biological information analysis,we screened differentially expressed miRNA,predicted target genes and seeked the miRNAs possibly related to neonatal breast milk jaundice.After words,the number of samples was expanded to 12cases/group,and the differences of hsa-miR-206,hsa-miR-224-5p,hsa-miR-409-3p,hsa-miR-574-3p and hsa-miR-127-3p expression between two groups were validated by the method of quantitative real-time PCR(qRT-PCR).Meanwhile,human milk macronutrients and energy analysis was performed by the MIRIS human milk analyzer;and the quantities of oleic acid,linoleic acid and DHA were analysed by the means of gas chromatography.We also discussed the possible correlation of macronutrients and fatty acids in human milk and the occurrence of and neonatal BMJ.All data were analyzed by SPSS version 22.0.Results:1.Human milk exosomes are rich in varieties of microrRNA,especially let-7g-5 p,let-7b-5p,has-miR-21-5p,has-miR-375,has-miR-99a-5p,has-miR-27a-3p,hasmiR-181-5p and has-miR-141-3p.2.Compared with control group,the expression levels of hsa-miR-409-3p,hsa-miR-574-3p and hsa-miR-127-3p in human milk exosomes of the BMJ group are significantly higher,and the difference the between two groups was statistically significant as determined by qRT-PCR(P values are 0.003,0.0002 and 0.002 respectively).3.The predicted target genes of hsa-miR-409-3p,hsa-miR-574-3p and hsa-miR-127-3p all include UGT1A1 gene.4.Both of quantity of 9-trans-oleic acid and DHA are obviously different between the BMJ group and the control group,and the difference between the two groups was statistically significant(P values are 0.03 and 0.005,respectively).5.The difference of macronutrients and energy in human milk between the BMJ group and the control group is statistically insignificant.Conclusions:1.Exosomes in human milk contain a variety of microRNAs,especially microRNAs associated with immune regulation as well as the growth and development of neonates.2.Exosomes in human milk of some miRNAs involved in regulation of neonatal bilirubin metabolism,of which hsa-miR-409-3p,hsa-miR-574-3p and hsa-miR-127-3p are possibly associated with the occurrence of newborn BMJ.The possble mechanism may be that these three miRNAs can regulate the expression of UGT1A1 gene,which has been demonsreated to related with the incidence of neonatal BMJ.3.The content of 9-trans-oleic acid and DHA in human mik may be associated with the occurrence of neonatal BMJ.