The Impact of microRNA-29a-3p on the Neural Stem Cell Differentiation Process into Neurons

To explore how microRNA-29a-3p influences the differentiation of neural stem cells into neurons and to identify any potential mechanisms involved. The program TargetScan, available online was utilized to examine and make predictions about the microRNA-29a-3p located upstream that regulate doublecortin X messenger ribonucleic acid. Ultimately, microRNA-29a-3p was preferred as the main central point of the investigation. The targeting of doublecortin X gene by microRNA-29a-3p was validated by employing a dual-luciferase reporter gene system. Before subjecting to adherent differentiation, the neural stem cells were transfected with microRNA-29a-3p inhibitor, microRNA-29a-3p mimic and normal control. MicroRNA and doublecortin X messenger ribonucleic acid levels were measured through quantitative reverse transcriptionpolymerase chain reaction and doublecortin X protein levels were determined through Western blot assays. The differentiation of neuronal precursor cells was detected by doublecortin X immunofluorescence. Neuronal differentiation was detected by microtubule-associated protein 2 immunofluorescence. According to the dual-luciferase reporter gene system, miR-29a-3p targeted the doublecortin X gene; microRNA-29a3p significantly decreased in differentiated cells for 3 d was observed, along with a significant reduction in levels of doublecortin X protein and messenger ribonucleic acid. On the other hand, a significant raise in microRNA-29a-3p in differentiated cells of microRNA-29a-3p mimic group for a period of 3 d was noticed with a significant drop in protein levels, doublecortin X messenger ribonucleic acid and doublecortin X immunofluorescence-positive neuronal precursor cells. From the microtubule-associated protein 2 immunofluorescence, it was confirmed that microRNA-29a-3p inhibitor group significantly elevated the total number of neurons, while microRNA-29a-3p mimic reduced the neurons on 7 d. Therefore, low expression of microRNA-29a-3p promote differentiation of neural stem cells into neurons via targeting doublecortin X.