Differences of miRMA expression signitures for blood samples of children with high blood lead level and low blood lead level

To further explore the effect of blood lead on miRNA expression in blood, children (aged 2-5 years) from kindergartens of Shaanxi province were divided into two groups and blood samples were collected. miRNA array was used to testify miRNA expression landscape between low blood lead level (BLL) group (0~ 50.00 g/L) and high BLL group (>50.00 g/L).Our data showed that 27 miRNAs were highly differentially expressed. Expression of miR-34b from this signiture was quantified by qRT-PCR,linear regression analysis showed that the correlation coefficient between blood lead level and miR-34b is 0.247, p <0.001, indicating that miR-34b was correlated with BLL. For miRNA array, 40 children were randomly selected from high BLL group (n= 20) and low BLL group (n= 20). General characteristics, including age, body mass index (BMI) and gender between these groups showed no significant difference. 250 μL of blood samples from each subject were blended to form a 4 ml plasma pool of each group. Then, miRNA array analysis was carried out to compare differences in miRNA expression profiles between these two groups.