Peer Review #3 of "Identification of microRNA signatures in umbilical cord blood associated with maternal characteristics (v0.1)"

Abstract

Background. Umbilical cord blood could serve as useful source of blood markers enabling more efficient and reliable prenatal and neonatal diagnostics. MicroRNAs (miRNAs) are ubiquitous in body fluids where they were used for detecting and monitoring various physiological and pathological conditions. In this descriptive study, we aimed to identify changes in miRNA expression profiles associated with basic maternal somatic and epidemiological characteristics.Methods. Study is based on 24 mothers from the Pilot phase of CELSPAC: TNG (Central European Longitudinal Studies of Parents and Children: The Next Generation) study. Cord blood was collected at time of delivery and global miRNA profiling was performed using microRNA Ready-to-use PCR Human Panel I+II TaqMan microarrays. Expression profiles were statistically evaluated in relation to maternal age, BMI, pregnancy weight gain, blood type, Rh factor status, allergies during pregnancy, addictive substance abuse and smoking status.Results. We analyzed expression of 752 human mature miRNAs in 24 samples of umbilical cord blood. For all maternal characteristics tested we described a specific signature of significantly deregulated miRNAs (P<0.05). Analysis revealed 7 miRNA associated with maternal age (3 increased and 4 decreased in women younger than 35 years), 14 miRNAs associated with BMI status (5 miRNAs increased and 9 miRNAs decreased in women with BMI>25) and 9 miRNAs associated with maternal weight gain during pregnancy (8 miRNAs increased, and 1 miRNA decreased in women with weight gain < 12 kg). Additionally, 17 miRNAs correlated to blood type (2 miRNAs decreased in blood type A, 11 increased in blood type B, 2 miRNAs increased in blood type AB and 2 miRNAs increased in blood type 0) and 17 miRNAs to Rh status of mother. We also detected 7 miRNAs deregulated in umbilical cord blood of women with allergy (4 increased and 3 decreased in women with allergy), 4 miRNAs associated to addictive substance abuse status (2 up-and 2 downregulated in women with addictive substance abuse) and 8 miRNAs associated with maternal cigarette smoking