The Search For Micrornas Potentially Involved In The Self-Renewal Maintaining Of Laboratory Rat Pluripotent Stem Cells

Self-renewal of cultured pluripotent stem cells is a complex process, which includes multiple functional and regulatory levels. Transcription factors, their target genes, chromatin modifiers, signaling pathways, and regulatory noncoding RNAs are involved in the maintaining of self-renewal. Studies of molecular and genetic bases of maintaining self-renewal and pluripotency in cultured mammalian cells are important to understand processes in preimplantation embryogenesis and to develop efficient techniques to obtain pluripotent stem cell lines for experimental biology and medicine. MicroRNAs (miRNAs) play an important role in pluripotency maintaining and reprogramming. However, involvement of this class of noncoding RNAs and functions of individual molecules are poorly studied. The goal of this study was the search for the miRNAs potentially involved in the pluripotency maintaining and reprogramming of Rattus norvegicus cells. We analyzed the expression of miRNAs in rat embryonic stem cells, induced pluripotent stem cells and embryonic fibroblasts using bioinformatic methods and data obtained with next generation sequencing. The analysis of differential expression between groups of rat pluripotent cells and fibroblasts, and the analysis of experimentally confirmed target genes of differentially expressed known rat miRNAs revealed novel potential players of pluripotency maintaining and reprogramming processes. In addition, novel members of these processes were revealed among novel rat miRNAs. The use of bioinformatic and systems biology approaches is the first step, which is necessary for choosing candidates for the subsequent experimental studies. The results obtained substantially improve our understanding of the self-renewal regulation system of the laboratory rat, a popular biomedical object, and our knowledge about the system in mammals.