Expression of microRNA (miR126*, miR155, miR21, miR29a) in breast milk cell fraction in women with hypertension: a comparative analysis with women without hypertension.

Objectives: The ideal option of food for a newborn's nourishment has traditionally been human breast milk (HBM). Previous studies have demonstrated a connection between the length of exclusively breastfeeding and its preventive effects on several conditions in neonates. Considering the significance of HBM, the study aimed at detecting the expression of microRNA (miR126*, miR155, miR21, and miR29a) in the breast milk cell fraction of women with hypertension. This was a cohort study of 35 postpartum women.

Material and methods: Five ml of milk was collected into a sterile container from patients in the morning on the second and third days after the labor. The collected milk has been centrifuged, total cellular RNA has been isolated from cell fraction from the collected milk, isolated RNA has been subject to qualitative and quantitative analysis, next reverse transcription has been conducted, followed by that, evaluation of the expression of the selected microRNA has been conducted using the synthesized cDNA. Finally, the tested microRNA's relative expression level has been calculated.

Results: Among patients with hypertension, the analysis of cell fraction of breast milk reported lower mean expression of miR126*, miR155, miR21, and miR29a as compared to patients without hypertension. Strong and very strong positive correlation between the expression of miR126* and miR155, miR126* and miR21, miR155 and miR21, miR 155 and miR29a, and miR 21 and miR29a have been noted.

Conclusions: Comparing patients with and without hypertension, it has been noted that patients with hypertension had lower mean expression of miR126*, miR155, miR21, and miR29a.