Vélez-Ixta Juan Manuel, Benítez-Guerrero Tizziani, Aguilera-Hernández Arlene, Martínez-Corona Helga, Corona-Cervantes Karina, Juárez-Castelán Carmen Josefina, Rangel-Calvillo Martín Noé, García-Mena Jaime
Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav), Av. Instituto Politécnico Nacional 2508, Ciudad de México 07360, Mexico.
Hospital General "Dr. José María Rodríguez", Instituto de Salud del Estado de Mexico, Ecatepec de Morelos 55200, Estado de México, Mexico.
BioTech (Basel). 2022 Apr 20;11(2):11. doi: 10.3390/biotech11020011.
Mammary gland secretory cells produce miRNA-rich milk. In humans, these miRNAs reach infant/neonate bloodstream, playing diverse roles, like neural system development, metabolism, and immune system maturation. Notwithstanding, still few works explore human milk miRNA content, and there are no reports at the population level. Our hypothesis was that miR-146b-5p, miR148a-3p, miR155-5p, mir181a-5p, and mir200a-3p immunoregulatory miRNAs are expressed in human colostrum/milk at a higher level than infant milk formulae. The aim of this work was to evaluate the expression of the five immunoregulatory miRNAs in human milk and compare it with their expression in infant milk formula. For this purpose, miRNA relative expression was measured by qPCR in cDNA prepared from total RNA extracted from sixty human colostrum/milk samples and six different formulae. The comparative Cт method 2 using exogenous cel-miR-39 as internal control was employed, followed by statistical analysis. We found the relative expression levels of miRNAs are comparable among colostrum/milk samples, and these miRNAs are present in infant milk formulae but at very low concentrations. We conclude that the relative expression of the immunomodulatory miRNAs is comparable in all the human colostrum/milk samples and is higher than the expression in formulae.
乳腺分泌细胞产生富含微小RNA（miRNA）的乳汁。在人类中，这些miRNA进入婴儿/新生儿的血液循环，发挥多种作用，如神经系统发育、新陈代谢和免疫系统成熟。尽管如此，仍很少有研究探讨人乳中的miRNA含量，且尚无群体水平的报道。我们的假设是，免疫调节性miRNA miR-146b-5p、miR148a-3p、miR155-5p、mir181a-5p和mir200a-3p在人初乳/乳汁中的表达水平高于婴儿配方奶粉。本研究的目的是评估这五种免疫调节性miRNA在人乳中的表达，并将其与在婴儿配方奶粉中的表达进行比较。为此，通过定量聚合酶链反应（qPCR）测定了从60份人初乳/乳汁样本和6种不同配方奶粉中提取的总RNA制备的互补DNA（cDNA）中miRNA的相对表达。采用以外源cel-miR-39为内参的比较Ct法2，随后进行统计分析。我们发现，初乳/乳汁样本中miRNA的相对表达水平相当，且这些miRNA存在于婴儿配方奶粉中，但浓度极低。我们得出结论，免疫调节性miRNA在所有人初乳/乳汁样本中的相对表达相当，且高于在配方奶粉中的表达。
