In vitro screening of LPS-induced miRNAs in leukocytes derived from cord blood and their possible roles in regulating MR signals

BACKGROUND: microRNAs (miRNAs) are involved in a wide variety of biological processes and play roles in the regulation of Toll-like receptor (TLR) signals. We hypothesized that lipopolysaccharide (LPS)-induced miRNAs in the leukocytes from cord blood (CB) play an important role in newborn innate immunity, specifically in the regulation of the TLR signaling pathway. METHODS: The expression profiles of LPS-induced miRNAs and TLR-related genes were studied by microarray and PCR arrays, respectively. A bioinformatics analysis was used to identify the potential biological processes and targets involved in the TLR signals affected by these miRNAs. RESULTS: A total of 85 miRNAs and 41 TLR-related genes were differentially expressed. The bioinformatics analysis showed that the potential target genes of these miRNAs were involved in regulation of cellular biosynthetic process, regulation of gene expression, regulation of macromolecule biosynthetic process, etc. Thirteen potential miRNA mRNA interaction sites were found within the cDNA sequences of 11 differentially expressed TLR signaling pathway genes. CONCLUSION: We identified a global miRNA expression signature occurring during LPS-induced acute inflammation in leukocytes derived from CB. The target genes were mainly involved in several biological processes, and these miRNAs may play important roles in the regulation of TLR signals. However, the precise mechanisms require further validation.